WO2016016937A1 - Brake system and brake control method - Google Patents

Brake system and brake control method Download PDF

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Publication number
WO2016016937A1
WO2016016937A1 PCT/JP2014/069885 JP2014069885W WO2016016937A1 WO 2016016937 A1 WO2016016937 A1 WO 2016016937A1 JP 2014069885 W JP2014069885 W JP 2014069885W WO 2016016937 A1 WO2016016937 A1 WO 2016016937A1
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Prior art keywords
vacuum
degree
brake
vacuum pump
continuous operation
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PCT/JP2014/069885
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French (fr)
Japanese (ja)
Inventor
慎太郎 表
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ニチユ三菱フォークリフト株式会社
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Priority to PCT/JP2014/069885 priority Critical patent/WO2016016937A1/en
Publication of WO2016016937A1 publication Critical patent/WO2016016937A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T17/00—Component parts, details, or accessories of power brake systems not covered by groups B60T8/00, B60T13/00 or B60T15/00, or presenting other characteristic features

Definitions

  • the present disclosure relates to the technical field of a brake system and a brake control method for adding an assisting force to a brake operation force by an operator using a negative pressure supplied from a vacuum pump.
  • a brake system which applies an assisting force to a brake operating force by an operator using a negative pressure supplied from a vacuum pump.
  • mechanical vacuum pumps were mainly used as vacuum pumps.
  • the mechanical vacuum pump is, for example, integrally formed with an alternator connected via a belt to the main shaft of the engine, and a negative pressure is generated by mechanically operating the vacuum pump together with the alternator as the main shaft rotates. generate.
  • Such a mechanical vacuum pump is disadvantageous because it consumes a part of the power of the engine, resulting in low efficiency and a low degree of freedom in layout.
  • Patent Document 1 discloses an example of a brake system using this type of electric vacuum pump, and by starting control of the electric vacuum pump at the timing when the detected value of negative pressure reaches the lower limit value, The degree of vacuum is maintained in an appropriate range.
  • Patent Document 1 Although a brake system using an electric vacuum pump is known as in Patent Document 1, the electric vacuum pump tends to have a relatively low negative pressure supply capability as compared with a mechanical vacuum pump, and its application is generally Currently, the required braking force is limited to a relatively small vehicle, such as a vehicle (car, etc.). On the other hand, in a heavy vehicle such as an industrial vehicle, the required braking force is large, so that a brake system using an electric vacuum pump has not been adopted. When introducing a brake system using an electric vacuum pump to an industrial vehicle, it is important to generate a large braking force by improving the negative pressure supply capability of the electric vacuum pump.
  • At least one embodiment of the present invention has been made in view of the above-mentioned problems, and provides a brake system and a brake control method capable of achieving efficiency improvement of negative pressure supply by an electric vacuum pump and prolongation of pump life. Intended to be provided.
  • a brake system provides a brake booster configured to assist a brake operating force by an operator, and supplies a negative pressure to the brake booster.
  • An electric vacuum pump configured in the above-described configuration, a vacuum degree detection unit configured to detect a vacuum degree in the brake booster, and a continuous operation time measurement unit configured to measure a continuous operation time of the electric vacuum pump
  • a pump control unit configured to control the electric vacuum pump based on the degree of vacuum detected by the degree of vacuum detection unit and the continuous operation time measured by the continuous operation time measurement unit;
  • the pump control unit is configured to set the degree of vacuum in advance.
  • the electric vacuum pump is configured to be stopped at either the timing when the value exceeds a predetermined upper limit value or the time when the continuous operation time becomes longer than a preset predetermined time, whichever is earlier. It is characterized by
  • the electric vacuum pump is stopped at a timing at which one of the vacuum degree and the continuous operation time reaches a predetermined threshold value as a control parameter.
  • the operating range of the electric vacuum pump can be limited to the range of low vacuum degree where recovery to the predetermined degree of vacuum is fast, so good negative pressure supply efficiency Is obtained.
  • the pump life can be extended by effectively shortening the operation period of the electric vacuum pump.
  • the pump control means operates the electric vacuum pump when the degree of vacuum is less than a predetermined lower limit value set in advance. And the measurement of the continuous operation time by the continuous operation time measuring means is started.
  • the vacuum degree can be maintained in an appropriate range by starting the negative pressure supply by the electric vacuum pump at the timing when the vacuum degree reaches the predetermined lower limit value. Further, by starting measurement by the continuous operation time measuring means at the start of operation of the electric vacuum pump, it is possible to effectively shorten the operation period of the electric vacuum pump and prolong the life of the pump.
  • the degree of vacuum when the continuous operation time measured by the continuous operation time measuring means reaches the predetermined time or more, the degree of vacuum is The system may further include a warning output unit configured to output a warning when the pressure is less than the predetermined lower limit value.
  • a warning output unit configured to output a warning when the pressure is less than the predetermined lower limit value.
  • the electric vacuum pump is supplied between the electric vacuum pump and the brake booster. May have a plurality of vacuum tanks configured to store negative pressure.
  • the electric vacuum pump by having a plurality of vacuum tanks that store negative pressure supplied from the electric vacuum pump, it is possible to increase the negative pressure capacity that can be accumulated and generate a larger braking force.
  • the degree of freedom in layout as compared to the case of having one large vacuum tank.
  • each of the plurality of vacuum tanks may be in communication so as to have the same degree of vacuum.
  • controllability can be improved as compared with the case where the degree of vacuum in each of the plurality of vacuum tanks is different, and the apparatus configuration can be simplified. You can do it.
  • the degree of vacuum of the vacuum tank attached to at least one vacuum tank of the plurality of vacuum tanks is the predetermined upper limit value
  • the first pressure switch configured to switch from the closed state to the open state when it is above
  • the degree of vacuum of the vacuum tank attached to at least one vacuum tank among the plurality of vacuum tanks is the predetermined lower limit value
  • a second pressure switch configured to switch from a closed state to an open state when the following occurs, and the vacuum degree detection unit is based on the open / closed states of the first pressure switch and the second pressure switch. It may be configured to detect the degree of vacuum in the brake booster.
  • the degree of vacuum in the brake booster can be easily detected based on the open / close states of the first pressure switch and the second pressure switch.
  • the first pressure switch and the second pressure switch are attached to at least one of the plurality of vacuum tanks. As long as it is done, there is a high degree of freedom in layout.
  • the first pressure switch and the second pressure switch may be respectively attached to each of the plurality of vacuum tanks.
  • the system can be improved in reliability by attaching the first pressure switch and the second pressure switch to each of the plurality of vacuum tanks.
  • An industrial vehicle includes the brake system described in the above (1) to (7).
  • the negative pressure supply capacity of the electric vacuum pump can be improved and a long pump life can be achieved. Therefore, the brake system can be mounted on an industrial vehicle heavier than ordinary vehicles (cars and the like).
  • a brake control method detects a degree of vacuum in a brake booster that assists a brake operating force by an operator in order to solve the above-mentioned problem; And a step of measuring a continuous operation time of the electric vacuum pump for supplying the vacuum pump and a case where the continuous operation time is longer than a predetermined time set in advance when the vacuum degree becomes larger than the predetermined upper limit set in advance. And a step of stopping the electric vacuum pump at any earlier timing.
  • the electric vacuum pump is operated when the degree of vacuum falls below a predetermined lower limit value, and the continuous operation is performed.
  • the method further comprises the step of starting measurement of the operating time.
  • the brake control method according to (10) when the continuous operation time reaches the predetermined time or more, the degree of vacuum is less than the predetermined lower limit.
  • the method further comprises the step of outputting a warning.
  • the brake control method described in the above (9) to (11) can be suitably implemented by the brake system described in the above (1) to (8).
  • the electric vacuum pump is stopped at timing when either one reaches a predetermined threshold.
  • the operating range of the electric vacuum pump can be limited to the range of low vacuum degree where recovery to the predetermined degree of vacuum is fast, so good negative pressure supply efficiency Is obtained.
  • the pump life can be extended by effectively shortening the operation period of the electric vacuum pump. As described above, in at least one embodiment of the present invention, it is possible to realize a brake system capable of achieving both improvement of the negative pressure supply capability of the electric vacuum pump and prolongation of the pump life.
  • FIG. 1 is a block diagram showing an overall configuration of a brake system according to an embodiment of the present invention. It is a schematic diagram which shows the drive circuit of a brake system. It is a graph which shows time transition of the degree of vacuum of the vacuum tank accompanying operation of an electric vacuum pump. It is a flowchart which shows the control content of the brake system by a controller. It is a graph which shows transition of the degree of vacuum at the time of operation of a brake system concerning one embodiment of the present invention. It is a graph which shows the other example of transition of the vacuum degree at the time of operation
  • expressions that indicate that things such as “identical”, “equal” and “homogeneous” are equal states not only represent strictly equal states, but also have tolerances or differences with which the same function can be obtained. It also represents the existing state.
  • expressions representing shapes such as quadrilateral shapes and cylindrical shapes not only represent shapes such as rectangular shapes and cylindrical shapes in a geometrically strict sense, but also uneven portions and chamfers within the range where the same effect can be obtained. The shape including a part etc. shall also be expressed.
  • the expressions “comprising”, “having”, “having”, “including” or “having” one component are not exclusive expressions excluding the presence of other components.
  • FIG. 1 is a block diagram showing an entire configuration of a brake system 1 according to an embodiment of the present invention.
  • the brake system 1 includes a brake booster 3 that applies an assisting force using a negative pressure supplied from the electric vacuum pump 7 as a boosting source with respect to the depression force of a brake pedal (not shown) by the operator at the driver's seat of the vehicle. ing.
  • the brake booster 3 increases the depression force of the brake pedal by the negative pressure supplied into the vacuum tank 2 and then transmits it to the master cylinder 4 to apply an assisting force to drive the brake ASSY 5.
  • negative pressure is consumed by introducing outside air into the vacuum tank 2 according to depression of the brake pedal, an air filter 6 is provided at the outside air intake port.
  • the vacuum tank 2 is connected to an electric vacuum pump 7 operable using electric energy stored in a battery or the like, and a negative pressure is supplied according to the operation of the electric vacuum pump 7.
  • a negative pressure is supplied according to the operation of the electric vacuum pump 7.
  • the vacuum tank 2 by configuring the vacuum tank 2 from a plurality of subtanks 2 a and 2 b, the amount of negative pressure capacity that can be accumulated is increased, thereby increasing the braking force that can be generated.
  • the vacuum tank 2 with the plurality of sub tanks 2a and 2b as described above, it is possible to increase the freedom of layout while securing a large negative pressure capacity in a limited space.
  • the two sub tanks 2a and 2b are in communication with each other, and are configured to have the same degree of vacuum.
  • the vacuum tank 2 is provided with a pressure switch 8 that automatically opens and closes at a predetermined degree of vacuum.
  • the first pressure switch 8a switches from the closed state to the open state when the degree of vacuum reaches P1 (for example 45 kPa) or higher, and the second pressure switch 8b switches from the closed state to the open state when the degree of vacuum exceeds P2 (for example 70 kPa) It is designed to replace it.
  • the third pressure switch 8c is designed to switch from the open state to the closed state when the degree of vacuum becomes P3 (e.g. 35 kPa) or less.
  • the first pressure switch 8a and the second pressure switch 8b are attached to the sub tanks 2a and 2b respectively, but as described above, all the sub tanks have the same degree of vacuum. Therefore, the first pressure switch 8a and the second pressure switch 8b may be attached to the sub tank 2a, or the first pressure switch 8a and the second pressure switch 8b may be attached to the sub tank 2b. Also, the reliability of the system may be improved by attaching the first pressure switch 8a and the second pressure switch 8b to the sub tanks 2a and 2b, respectively.
  • the buzzer 9 is a means for notifying the operator by emitting a warning sound (which is not limited in a range detectable by the operator's five senses) when an abnormality occurs in the brake system 1.
  • the controller 10 is a control unit that controls the operation control of the brake system 1.
  • FIG. 1 shows the internal configuration of the controller 10 as a functional block, and the degree of vacuum in the brake booster 3 is determined based on the pump control means 13 for controlling the electric vacuum pump 7, and the open and closed states of the first pressure switch and the second pressure switch.
  • the apparatus comprises a vacuum degree detecting means 14 for detecting, a continuous operating time measuring means 15 for measuring the continuous operating time of the electric vacuum pump 7, and a warning output means 16 for controlling the operation of the buzzer 9b.
  • FIG. 2 is a schematic view showing a drive circuit of the brake system 1.
  • the controller 10 has terminals 10a to 10f, and the operation control of the electric vacuum pump 7 is carried out based on the electric signals transmitted and received at each terminal.
  • the terminal 10 a is connected to the high potential line 11 (+12 V), and the driving power of the controller 10 is input.
  • the terminal 10b and the terminal 10c are connected to the high potential line 11 via the first pressure switch 8a and the second pressure switch 8b, respectively.
  • the first pressure switch 8a and the second pressure switch 8b are set in the closed state in the initial state, and are switched to the open state when the degree of vacuum of the vacuum tank 2 reaches less than the respective threshold values.
  • the terminals 10 b and 10 c are shorted to the high potential line 11.
  • the controller 10 can grasp the open / close state of the first pressure switch 8a and the second pressure switch 8b based on the potential detection at the terminal 10b and the terminal 10c.
  • the terminal 10d is a ground terminal.
  • a buzzer 9b is connected to the terminal 10e, and the buzzer 9 is turned on / off in accordance with a control signal input from the controller 10 via the connection line.
  • a control relay 12 for turning on / off the electric vacuum pump 7 is connected to the terminal 10f.
  • the controller 10 outputs a control signal (control current) of the electric vacuum pump 7 from the terminal 10f, and the switch 12b is controlled to be switched ON / OFF by exciting the coil portion 12a of the control relay 12 connected to the terminal 10f. Ru.
  • the control relay 12 When the control relay 12 is turned on, electric power for driving is supplied to the electric vacuum pump 7 from the high potential line 11, and the electric vacuum pump 7 is started.
  • the buzzer 9a is connected to the high potential line 11 via the third pressure switch 8c.
  • the third pressure switch 8c is set to an open state in the initial state, and switches to a closed state when the degree of vacuum of the vacuum tank 2 reaches the respective threshold value or less.
  • FIG. 3 is a graph showing the time course of the degree of vacuum P of the vacuum tank 2 as the electric vacuum pump 7 is operated.
  • the threshold value P1 shown in FIG. 3 is defined as the lower limit value of the degree of vacuum necessary to apply a sufficient assisting force to the brake pedal, and is required, for example, to generate the braking force required by the legal standard.
  • the degree of vacuum is defined with a certain margin for safety.
  • the degree of vacuum P increases logarithmically with time, and after a certain amount of time passes, the degree of vacuum P converges toward a certain constant value.
  • the negative pressure supply efficiency of the electric vacuum pump 7 tends to become lower as the vacuum degree P of the vacuum tank 2 becomes higher, and the threshold P2 shown in FIG. 3 is the upper limit vacuum in the range where good negative pressure supply efficiency can be obtained.
  • a value of about 70% of the convergence value may be adopted.
  • the electric vacuum pump 7 is controlled to operate in the range of P1 ⁇ P ⁇ P2, but in this range, the operator can operate the brake pedal multiple times. It is preferable to set to such an extent that a certain width can be secured, but specifically, it may be determined in consideration of the characteristics of the electric vacuum pump and the like.
  • FIG. 4 is a flowchart showing the control contents of the brake system 1 by the controller 10.
  • the controller 10 determines whether the second pressure switch 8b is in the closed state (step S101). As described above, since the second pressure switch 8b is switched to the open state when the degree of vacuum P of the vacuum tank 2 is the threshold P2 or more, whether or not the degree of vacuum P is substantially lower than the threshold P2 in step S101 Can be determined. When it is determined that the second pressure switch 8b is in the closed state (step S101: YES), the controller 10 (vacuum degree detection means 14) further determines whether or not the first pressure switch 8a is in the closed state ( Step S102).
  • the vacuum degree P of the vacuum tank 2 is in an appropriate range (P1 ⁇ P ⁇ P2) by detecting the open / close states of the first pressure switch 8a and the second pressure switch 8b. Logic is formed to determine whether or not.
  • step S102 determines that the degree of vacuum P is in the range of P ⁇ P1, that is, the degree of vacuum P is below the lower limit. 10 performs the following control in the pump control means 13 to start the electric vacuum pump 7 and start negative pressure supply.
  • the controller 10 determines whether the control relay 12 is OFF or not by monitoring the value of the control current output from the terminal 10f (step S103).
  • step S103 YES
  • the controller 10 outputs a control current from the terminal 10f to turn on the control relay to start the electric vacuum pump 7, and the continuous operation time of the electric vacuum pump 7 Measurement of T is started (step S104).
  • the electric vacuum pump 7 is started to supply a negative pressure to the brake booster 3 so that the braking force of the brake system 1 can be managed in an appropriate range. Further, by starting measurement of the continuous operation time T in the continuous operation time measuring means 15 at the same time when the operation of the electric vacuum pump 7 is started, the operation period of the electric vacuum pump 7 is shortened and the electric vacuum pump 7 is frequently turned on. This prevents the pump from being turned off and prolongs the pump life.
  • the predetermined time T1 it may be set as a period necessary for increasing the degree of vacuum from the threshold value P1 to the threshold value P2 by the electric vacuum pump 7 while the depression operation of the brake pedal by the operator is performed at least once. .
  • step S103 If the control relay 12 has already been turned on in step S103 (step S103: NO), the continuous operation time T of the electric vacuum pump 7 reaches the predetermined time T1 based on the measurement result of the continuous operation time measuring means 15 It is determined whether or not (step S105). If the continuous operation time T has not reached the predetermined time T1 (step S105: YES), the controller 10 returns the process to step S104, and the operation of the electric vacuum pump 7 and the measurement of the continuous operation time T by the continuous operation time measuring means 15 To continue.
  • step S105 the controller 10 switches the control relay 12 to OFF to stop the electric vacuum pump 7 and continuously
  • the measurement of the operating time T is initialized (step S106).
  • an error signal of The error signal is for notifying the operator that the continuous operation time T has reached the predetermined time T1, and is notified to the operator by operating the buzzer 9b. Note that a lamp provided at a position within the field of view of the operator may be operated.
  • step S101 when it is determined in step S101 that the second pressure switch 8b is in the open state (step S101: NO), the controller 10 controls the vacuum degree P in the range of P2 ⁇ P, that is, the vacuum degree P is high. It is determined that the negative pressure supply efficiency 7 is not sufficiently obtained (see FIG. 3), and the control relay 12 is turned off by the pump control means 13 to stop the electric vacuum pump 7 (step S107). At this time, the measurement of the continuous operation time T is also initialized.
  • step S102 When it is determined in step S102 that the first pressure switch 8a is in the open state (step S102: NO), the controller 10 (vacuum degree detection unit 14) determines that the vacuum degree P is in the range of P1 ⁇ P ⁇ P2. Do. In this case, the controller 10 determines whether the control relay 12 is off, thereby confirming the operating state of the electric vacuum pump 7 (step S108). If the control relay 12 is OFF (step S108: YES), the stop state of the electric vacuum pump 7 is continued and the continuous operation time T is initialized (step S109).
  • step S108 When the control relay 12 is ON at step S108 (step S108: NO), the controller 10 determines whether the measured continuous operation time T has reached a predetermined time T1 (step S110). If the continuous operation time T has not reached the predetermined time T1 (step S110: YES), the controller 10 continues the operation of the electric vacuum pump 7 and the integration of the continuous operation time T (step S111). Thereafter, when the continuous operation time T reaches the predetermined time T1 (step S110: NO), the controller 10 turns off the control relay 12 to stop the electric vacuum pump 7 and initialize the continuous operation time T (step S112). ).
  • FIG. 5 is a graph showing the transition of the degree of vacuum P of the vacuum tank 2 at the time of operation of the brake system 1 according to an embodiment of the present invention.
  • the degree of vacuum P is lowered substantially in a step-like manner by the introduction of external air into the vacuum tank 2 each time the brake pedal is depressed.
  • the degree of vacuum P reaches the threshold value P1
  • the electric vacuum pump 7 is started, and the negative pressure supply to the vacuum tank 2 is started (step S104 in FIG. 4).
  • the degree of vacuum P increases logarithmically (see FIG. 3), but in FIG. 5, the brake pedal is depressed even while the electric vacuum pump 7 is operating.
  • the threshold value P3 which is the starting condition of the buzzer 9a may be set to a degree of vacuum required to generate the braking force required by the strictest legal standard among a plurality of legal standards.
  • the degree of vacuum required to generate the braking force required by the strictest legal standards was defined with a certain margin to the degree of vacuum required to generate the braking force required by legal standards.
  • the value is lower by a certain margin than the threshold value P1. This constant margin is set so as not to fall below the braking force required by the strictest legal standard even if there is a momentary delay between the command from the controller 10 and the operation of the electric vacuum pump 7.
  • FIG. 6 is a graph showing another example of the transition of the degree of vacuum P when the brake system 1 according to the embodiment of the present invention is in operation.
  • FIG. 6 shows a case where the depression amount of the brake pedal during the operation of the electric vacuum pump 7 is larger than that in the case of FIG.
  • the electric vacuum pump 7 operates as in FIG. 5, and thereafter the degree of vacuum increases in a pulse according to the depression timing of the brake pedal.
  • the electric vacuum pump is stopped when the continuous operation time T reaches the predetermined time T1 before the vacuum degree reaches the threshold value P2 (step in FIG. 4) See S110).
  • FIG. 7 is a graph showing transition of the degree of vacuum P when an abnormality occurs in the brake system 1 according to an embodiment of the present invention.
  • FIG. 7 also shows the operating state of the buzzer 9b due to the detection of an abnormality.
  • the vacuum degree P reaches the threshold value P1 by the depression of the brake pedal
  • the electric vacuum pump 7 operates as in FIG. 5, but the vacuum degree P of the vacuum tank 2 does not increase and is less than the threshold value P1. State continues for a predetermined time T1.
  • the warning output means 16 of the controller 10 notifies the operator by operating the buzzer 9b.
  • the warning output means 16 may operate a lamp provided at a position that is within the field of view of the operator (see step S106 in FIG. 4).
  • the electric vacuum pump is operated at a timing when one of the vacuum degree P and the continuous operation time T has reached a predetermined threshold value. Stop 7 If the electric vacuum pump 7 is stopped when the degree of vacuum P becomes larger than the threshold P2, the operating range of the electric vacuum pump 7 can be limited to a range where the degree of vacuum is relatively low, so that a good negative pressure supply efficiency can be obtained. Since the pump load can be operated in a low area, the pump life can be extended. Further, when the electric vacuum pump 7 is stopped when the continuous operation time T becomes longer than the predetermined period T1, the pump life can be extended by effectively shortening the operation period of the electric vacuum pump 7.
  • the electric vacuum pump having a relatively small capacity can be used, and the cost reduction and the reduction in size and space saving of the brake system can be achieved.
  • the electric vacuum pump can be operated with electrical energy, it is not necessary to always be on like the mechanical vacuum pump driven by the power of the engine, so the efficiency is high and it is easy by removing the wiring. Since it can be retrofitted, it has a high degree of freedom in layout. Moreover, since it can be controlled electrically, it is excellent in controllability.
  • the brake system 1 can improve the negative pressure supply capacity of the electric vacuum pump 7 and achieve a long pump life, it can be mounted on a heavy industrial vehicle as compared to a general vehicle (such as a passenger car). Become.
  • At least one embodiment of the present invention can be used for a brake system and a brake control method that apply an assisting force to a brake operating force by an operator using a negative pressure supplied from a vacuum pump.

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  • Engineering & Computer Science (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Valves And Accessory Devices For Braking Systems (AREA)

Abstract

The present invention has the purpose of providing a brake system and brake control method capable of efficiently supplying negative pressure by an electric vacuum pump and prolonging the pump life span. The brake system is provided with an electric vacuum pump (7) for supplying negative pressure to a brake booster (3), and stops the electric vacuum pump when the level of vacuum in the brake booster exceeds a preset upper limit, or when the continuous operating time of the electric vacuum pump becomes longer than a preset time period, whichever occurs earlier. As a result, the negative pressure supply efficiency of the electric vacuum pump can be raised and the pump life span can be prolonged.

Description

ブレーキシステム及びブレーキ制御方法Brake system and brake control method
　本開示はバキュームポンプからの供給負圧を利用して、オペレータによるブレーキ操作力に助勢力を付加するブレーキシステム及びブレーキ制御方法の技術分野に関する。 The present disclosure relates to the technical field of a brake system and a brake control method for adding an assisting force to a brake operation force by an operator using a negative pressure supplied from a vacuum pump.
　バキュームポンプからの供給負圧を利用して、オペレータによるブレーキ操作力に助勢力を付加するブレーキシステムが知られている。従来、バキュームポンプとして主に機械式のバキュームポンプが使用されていた。機械式のバキュームポンプは、例えばエンジンの主軸にベルトを介して繋がれたオルタネータと一体的に構成されており、主軸の回転に伴ってオルタネータと共にバキュームポンプが機械的に作動することによって負圧を発生させる。このような機械式バキュームポンプはエンジンの動力の一部を消費するため効率が低くなること、そして、レイアウト上の自由度が低いことがデメリットとなる。 There is known a brake system which applies an assisting force to a brake operating force by an operator using a negative pressure supplied from a vacuum pump. In the past, mechanical vacuum pumps were mainly used as vacuum pumps. The mechanical vacuum pump is, for example, integrally formed with an alternator connected via a belt to the main shaft of the engine, and a negative pressure is generated by mechanically operating the vacuum pump together with the alternator as the main shaft rotates. generate. Such a mechanical vacuum pump is disadvantageous because it consumes a part of the power of the engine, resulting in low efficiency and a low degree of freedom in layout.
　近年、このような機械式のバキュームポンプに代えて、電動式のバキュームポンプの普及が進んでいる。
　例えば特許文献１には、この種の電動式バキュームポンプを用いたブレーキシステムの一例が開示されており、負圧の検出値が下限値に到達するタイミングで電動バキュームポンプを始動制御することで、真空度を適切な範囲に維持している。 In recent years, in place of such mechanical vacuum pumps, motorized vacuum pumps have been widely used.
For example, Patent Document 1 discloses an example of a brake system using this type of electric vacuum pump, and by starting control of the electric vacuum pump at the timing when the detected value of negative pressure reaches the lower limit value, The degree of vacuum is maintained in an appropriate range.
特開２００６－１４２９４２号公報Unexamined-Japanese-Patent No. 2006-142942
　特許文献１のように電動式バキュームポンプを利用したブレーキシステムが知られているものの、電動式バキュームポンプは機械式バキュームポンプに比べて負圧供給能力が比較的低い傾向にあり、その用途は一般車両（乗用車等）のように、要求される制動力が比較的小さな車両に限られているのが現状である。一方、産業車両のような重量の大きな車両では要求される制動力が大きいため、電動式バキュームポンプを用いたブレーキシステムを採用するに至っていない。産業車両に電動式バキュームポンプを用いたブレーキシステムを導入する場合、電動式バキュームポンプの負圧供給能力を向上することによって大きな制動力を発生させることが重要な課題となる。 Although a brake system using an electric vacuum pump is known as in Patent Document 1, the electric vacuum pump tends to have a relatively low negative pressure supply capability as compared with a mechanical vacuum pump, and its application is generally Currently, the required braking force is limited to a relatively small vehicle, such as a vehicle (car, etc.). On the other hand, in a heavy vehicle such as an industrial vehicle, the required braking force is large, so that a brake system using an electric vacuum pump has not been adopted. When introducing a brake system using an electric vacuum pump to an industrial vehicle, it is important to generate a large braking force by improving the negative pressure supply capability of the electric vacuum pump.
　本発明の少なくとも一実施形態は上述の問題点に鑑みてなされたものであり、電動バキュームポンプによる負圧供給の効率化、及び、ポンプ寿命の長期化を達成可能なブレーキシステム及びブレーキ制御方法を提供することを目的とする。 SUMMARY OF THE INVENTION At least one embodiment of the present invention has been made in view of the above-mentioned problems, and provides a brake system and a brake control method capable of achieving efficiency improvement of negative pressure supply by an electric vacuum pump and prolongation of pump life. Intended to be provided.
　（１）本発明の少なくとも一実施形態に係るブレーキシステムは上記課題を解決するために、オペレータによるブレーキ操作力を補助するように構成されたブレーキブースタと、前記ブレーキブースタに負圧を供給するように構成された電動バキュームポンプと、前記ブレーキブースタにおける真空度を検出するように構成された真空度検出手段と、前記電動バキュームポンプの連続運転時間を計測するように構成された連続運転時間計測手段と、前記真空度検出手段によって検出された真空度、及び、前記連続運転時間計測手段によって計測された連続運転時間に基づいて、前記電動バキュームポンプを制御するように構成されたポンプ制御手段とを備えるブレーキシステムであって、前記ポンプ制御手段は、前記真空度が予め設定された所定上限値より大きくなった場合と、前記連続運転時間が予め設定された所定時間より長くなった場合とのいずれか早い方のタイミングで、前記電動バキュームポンプを停止させるように構成されていることを特徴とする。 (1) In order to solve the above problems, a brake system according to at least one embodiment of the present invention provides a brake booster configured to assist a brake operating force by an operator, and supplies a negative pressure to the brake booster. An electric vacuum pump configured in the above-described configuration, a vacuum degree detection unit configured to detect a vacuum degree in the brake booster, and a continuous operation time measurement unit configured to measure a continuous operation time of the electric vacuum pump A pump control unit configured to control the electric vacuum pump based on the degree of vacuum detected by the degree of vacuum detection unit and the continuous operation time measured by the continuous operation time measurement unit; The pump control unit is configured to set the degree of vacuum in advance. The electric vacuum pump is configured to be stopped at either the timing when the value exceeds a predetermined upper limit value or the time when the continuous operation time becomes longer than a preset predetermined time, whichever is earlier. It is characterized by
　本発明の少なくとも一実施形態にかかるブレーキシステムによれば、真空度及び連続運転時間を制御パラメータとして、いずれか一方が所定の閾値に達したタイミングで電動バキュームポンプを停止させる。真空度が所定上限値より大きくなった場合に電動バキュームポンプを停止すると、電動バキュームポンプの動作範囲を所定の真空度に対する回復が速い低真空度の範囲に限定できるので、良好な負圧供給効率が得られる。また、連続運転時間が所定期間より長くなった場合に電動バキュームポンプを停止すると、電動バキュームポンプの動作期間を効率的に短縮することで、ポンプ寿命を長期化することができる。このように本発明では、電動バキュームポンプの負圧供給能力の向上とポンプ寿命の長期化を両立可能なブレーキシステムを実現することができる。 According to the brake system according to at least one embodiment of the present invention, the electric vacuum pump is stopped at a timing at which one of the vacuum degree and the continuous operation time reaches a predetermined threshold value as a control parameter. When the electric vacuum pump is stopped when the degree of vacuum exceeds the predetermined upper limit value, the operating range of the electric vacuum pump can be limited to the range of low vacuum degree where recovery to the predetermined degree of vacuum is fast, so good negative pressure supply efficiency Is obtained. In addition, when the electric vacuum pump is stopped when the continuous operation time is longer than the predetermined period, the pump life can be extended by effectively shortening the operation period of the electric vacuum pump. As described above, according to the present invention, it is possible to realize a brake system capable of achieving both improvement of the negative pressure supply capability of the electric vacuum pump and prolongation of the pump life.
　（２）幾つかの実施形態では、上記（１）に記載のブレーキシステムにおいて、前記ポンプ制御手段は、前記真空度が予め設定された所定下限値未満になった時に、前記電動バキュームポンプを作動させると共に、前記連続運転時間計測手段による前記連続運転時間の計測を開始させるように構成されている。
　この実施形態によれば、真空度が所定下限値になるタイミングで電動バキュームポンプによる負圧供給を開始することで、真空度を適切な範囲に維持できる。また、電動バキュームポンプの作動開始と共に連続運転時間計測手段により計測を開始することによって、電動バキュームポンプの動作期間を効率的に短縮して、ポンプ寿命の長期化を図ることができる。 (2) In some embodiments, in the brake system according to the above (1), the pump control means operates the electric vacuum pump when the degree of vacuum is less than a predetermined lower limit value set in advance. And the measurement of the continuous operation time by the continuous operation time measuring means is started.
According to this embodiment, the vacuum degree can be maintained in an appropriate range by starting the negative pressure supply by the electric vacuum pump at the timing when the vacuum degree reaches the predetermined lower limit value. Further, by starting measurement by the continuous operation time measuring means at the start of operation of the electric vacuum pump, it is possible to effectively shorten the operation period of the electric vacuum pump and prolong the life of the pump.
　（３）幾つかの実施形態では、上記（２）に記載のブレーキシステムにおいて、前記連続運転時間計測手段によって計測された前記連続運転時間が前記所定時間以上に達した場合に、前記真空度が前記所定下限値未満である場合に警告を出力するように構成された警告出力手段を備えてもよい。
　この実施形態では、電動バキュームポンプの作動開始後、連続運転時間が所定時間以上に達したにもかかわらず、真空度が予定下限値未満である場合には、当該ブレーキシステムに何らかの不具合（例えば電動バキュームポンプの故障や、負圧を蓄積する真空タンクの漏れなど）が考えられるため、警報を出力することによってオペレータに迅速に報知し、重大な不具合に発展することを防止することができる。 (3) In some embodiments, in the brake system according to (2), when the continuous operation time measured by the continuous operation time measuring means reaches the predetermined time or more, the degree of vacuum is The system may further include a warning output unit configured to output a warning when the pressure is less than the predetermined lower limit value.
In this embodiment, even if the continuous operation time has reached a predetermined time or more after the start of operation of the electric vacuum pump, if the degree of vacuum is less than the planned lower limit value, the brake system is in trouble (for example, the motor system) Since a failure of the vacuum pump, a leak of a vacuum tank that accumulates a negative pressure, and the like can be considered, it is possible to quickly notify the operator by outputting an alarm and prevent the development of a serious failure.
　（４）幾つかの実施形態では、上記（１）～（３）のいずれか一つに記載
のブレーキシステムにおいて、前記電動バキュームポンプと前記ブレーキブースタとの間に、前記電動バキュームポンプから供給された負圧を蓄えるように構成された複数の真空タンクを有してもよい。
　この実施形態では、電動バキュームポンプから供給された負圧を蓄える真空タンクを複数有することによって、蓄積可能な負圧容量を増加し、より大きな制動力を発生することが可能となる。特に真空タンクを複数有することにより、一つの大きな真空タンクを有する場合に比べてレイアウト上の自由度を上げることができる。 (4) In some embodiments, in the brake system according to any one of (1) to (3), the electric vacuum pump is supplied between the electric vacuum pump and the brake booster. May have a plurality of vacuum tanks configured to store negative pressure.
In this embodiment, by having a plurality of vacuum tanks that store negative pressure supplied from the electric vacuum pump, it is possible to increase the negative pressure capacity that can be accumulated and generate a larger braking force. In particular, by having a plurality of vacuum tanks, it is possible to increase the degree of freedom in layout as compared to the case of having one large vacuum tank.
　（５）幾つかの実施形態では、上記（４）に記載のブレーキシステムにおいて、前記複数の真空タンクの各々は、真空度が同じになるように連通されているとよい。
　この実施形態では、複数の真空タンクにおける各々の真空度が同じのため、複数の真空タンクにおける各々の真空度が異なる場合と比べて、制御性を向上させることが出来るとともに、装置構成をシンプルにすることが出来る。 (5) In some embodiments, in the brake system according to (4), each of the plurality of vacuum tanks may be in communication so as to have the same degree of vacuum.
In this embodiment, since the degree of vacuum in each of the plurality of vacuum tanks is the same, controllability can be improved as compared with the case where the degree of vacuum in each of the plurality of vacuum tanks is different, and the apparatus configuration can be simplified. You can do it.
　（６）幾つかの実施形態では、上記（５）に記載のブレーキシステムにおいて、前記複数の真空タンクの内の少なくとも一つの真空タンクに取り付けられた、前記真空タンクの真空度が前記所定上限値以上になると閉状態から開状態に切り替わるように構成された第１圧力スイッチと、前記複数の真空タンクの内の少なくとも一つの真空タンクに取り付けられた、前記真空タンクの真空度が前記所定下限値以下になると閉状態から開状態に切か替わるように構成された第２圧力スイッチと、をさらに備え、前記真空度検出手段は、前記第１圧力スイッチおよび前記第２圧力スイッチの開閉状態に基づいて前記ブレーキブースタにおける真空度を検出するように構成されているとよい。 (6) In some embodiments, in the brake system according to (5), the degree of vacuum of the vacuum tank attached to at least one vacuum tank of the plurality of vacuum tanks is the predetermined upper limit value The first pressure switch configured to switch from the closed state to the open state when it is above, and the degree of vacuum of the vacuum tank attached to at least one vacuum tank among the plurality of vacuum tanks is the predetermined lower limit value And a second pressure switch configured to switch from a closed state to an open state when the following occurs, and the vacuum degree detection unit is based on the open / closed states of the first pressure switch and the second pressure switch. It may be configured to detect the degree of vacuum in the brake booster.
　この実施形態では、第１圧力スイッチと第２圧力スイッチの開閉状態に基づいて、簡単にブレーキブースタにおける真空度を検出することが出来る。この際、複数の真空タンクの各々は、真空度が同じになるように連通されているため、第１圧力スイッチおよび第２圧力スイッチは、複数の真空タンクの内の少なくとも一つの真空タンクに取り付けられていればよく、レイアウト上の自由度が高い。 In this embodiment, the degree of vacuum in the brake booster can be easily detected based on the open / close states of the first pressure switch and the second pressure switch. At this time, since each of the plurality of vacuum tanks is communicated so as to have the same degree of vacuum, the first pressure switch and the second pressure switch are attached to at least one of the plurality of vacuum tanks. As long as it is done, there is a high degree of freedom in layout.
　（７）幾つかの実施形態では、前記第１圧力スイッチおよび前記第２圧力スイッチは、前記複数の真空タンクの各々に夫々取り付けられているとよい。 (7) In some embodiments, the first pressure switch and the second pressure switch may be respectively attached to each of the plurality of vacuum tanks.
　この実施形態では、第１圧力スイッチおよび第２圧力スイッチを、複数の真空タンクの各々に夫々取り付けることで、システムの信頼性を向上させることが出来る。 In this embodiment, the system can be improved in reliability by attaching the first pressure switch and the second pressure switch to each of the plurality of vacuum tanks.
　（８）本発明の一実施形態にかかる産業用車輌は、上記（１）～（７）に記載のブレーキシステムを備えている。
　このように上記ブレーキシステムでは電動バキュームポンプの負圧供給能力を向上すると共に長いポンプ寿命を達成できるので、一般車両（乗用車等）に比べて車重の重い産業車両への搭載が可能となる。 (8) An industrial vehicle according to an embodiment of the present invention includes the brake system described in the above (1) to (7).
As described above, in the above-described brake system, the negative pressure supply capacity of the electric vacuum pump can be improved and a long pump life can be achieved. Therefore, the brake system can be mounted on an industrial vehicle heavier than ordinary vehicles (cars and the like).
　（９）本発明の少なくとも一実施形態にかかるブレーキ制御方法は、上記課題を解決するために、オペレータによるブレーキ操作力を補助するブレーキブースタにおける真空度を検出する工程と、前記ブレーキブースタに負圧を供給する電動バキュームポンプの連続運転時間を計測する工程と、前記真空度が予め設定された所定上限値より大きくなったと、前記連続運転時間が予め設定された所定時間より長くなった場合とのいずれか早い方のタイミングで、前記電動バキュームポンプを停止させる工程と、備えることを特徴とする。 (9) A brake control method according to at least one embodiment of the present invention detects a degree of vacuum in a brake booster that assists a brake operating force by an operator in order to solve the above-mentioned problem; And a step of measuring a continuous operation time of the electric vacuum pump for supplying the vacuum pump and a case where the continuous operation time is longer than a predetermined time set in advance when the vacuum degree becomes larger than the predetermined upper limit set in advance. And a step of stopping the electric vacuum pump at any earlier timing.
　（１０）幾つかの実施形態では、上記（９）に記載のブレーキ制御方法において、前記真空度が予め設定された所定下限値未満になった時に、前記電動バキュームポンプを作動させると共に、前記連続運転時間の計測を開始する工程をさらに備える。 (10) In some embodiments, in the brake control method according to (9), the electric vacuum pump is operated when the degree of vacuum falls below a predetermined lower limit value, and the continuous operation is performed. The method further comprises the step of starting measurement of the operating time.
　（１１）幾つかの実施形態では、上記（１０）に記載のブレーキ制御方法において、前記連続運転時間が前記所定時間以上に達した際に、前記真空度が前記所定下限値未満である場合に警告を出力する工程をさらに備える。 (11) In some embodiments, in the brake control method according to (10), when the continuous operation time reaches the predetermined time or more, the degree of vacuum is less than the predetermined lower limit. The method further comprises the step of outputting a warning.
　このような上記（９）～（１１）に記載のブレーキ制御方法は、上記（１）～（８）に記載のブレーキシステムによって好適に実施することが可能である。 The brake control method described in the above (9) to (11) can be suitably implemented by the brake system described in the above (1) to (8).
　本発明の少なくとも一実施形態によれば、真空度及び連続運転時間を制御パラメータとして、いずれか一方が所定の閾値に達したタイミングで電動バキュームポンプを停止させる。真空度が所定上限値より大きくなった場合に電動バキュームポンプを停止すると、電動バキュームポンプの動作範囲を所定の真空度に対する回復が速い低真空度の範囲に限定できるので、良好な負圧供給効率が得られる。また、連続運転時間が所定期間より長くなった場合に電動バキュームポンプを停止すると、電動バキュームポンプの動作期間を効率的に短縮することで、ポンプ寿命を長期化することができる。このように本発明の少なくとも一実施形態では、電動バキュームポンプの負圧供給能力の向上とポンプ寿命の長期化を両立可能なブレーキシステムを実現することができる。 According to at least one embodiment of the present invention, using the degree of vacuum and the continuous operation time as control parameters, the electric vacuum pump is stopped at timing when either one reaches a predetermined threshold. When the electric vacuum pump is stopped when the degree of vacuum exceeds the predetermined upper limit value, the operating range of the electric vacuum pump can be limited to the range of low vacuum degree where recovery to the predetermined degree of vacuum is fast, so good negative pressure supply efficiency Is obtained. In addition, when the electric vacuum pump is stopped when the continuous operation time is longer than the predetermined period, the pump life can be extended by effectively shortening the operation period of the electric vacuum pump. As described above, in at least one embodiment of the present invention, it is possible to realize a brake system capable of achieving both improvement of the negative pressure supply capability of the electric vacuum pump and prolongation of the pump life.
本発明の一実施形態に係るブレーキシステムの全体構成を示すブロック図である。1 is a block diagram showing an overall configuration of a brake system according to an embodiment of the present invention. ブレーキシステムの駆動回路を示す模式図である。It is a schematic diagram which shows the drive circuit of a brake system. 電動バキュームポンプを動作に伴う真空タンクの真空度の時間推移を示すグラフである。It is a graph which shows time transition of the degree of vacuum of the vacuum tank accompanying operation of an electric vacuum pump. コントローラによるブレーキシステムの制御内容を示すフローチャートである。It is a flowchart which shows the control content of the brake system by a controller. 本発明の一実施形態に係るブレーキシステムの動作時における真空度の推移を示すグラフである。It is a graph which shows transition of the degree of vacuum at the time of operation of a brake system concerning one embodiment of the present invention. 本発明の一実施形態に係るブレーキシステムの動作時における真空度の推移の他の例を示すグラフである。It is a graph which shows the other example of transition of the vacuum degree at the time of operation | movement of the brake system which concerns on one Embodiment of this invention. 本発明の一実施形態に係るブレーキシステムに異常が発生した場合における真空度の推移を示すグラフである。It is a graph which shows transition of the degree of vacuum in, when abnormalities generate | occur | produce in the brake system which concerns on one Embodiment of this invention.
　以下、添付図面を参照して本発明の幾つかの実施形態について説明する。ただし、実施形態として記載されている又は図面に示されている構成部品の寸法、材質、形状、その相対的配置等は、本発明の範囲をこれに限定する趣旨ではなく、単なる説明例にすぎない。
　例えば、「ある方向に」、「ある方向に沿って」、「平行」、「直交」、「中心」、「同心」或いは「同軸」等の相対的或いは絶対的な配置を表す表現は、厳密にそのような配置を表すのみならず、公差、若しくは、同じ機能が得られる程度の角度や距離をもって相対的に変位している状態も表すものとする。
　例えば、「同一」、「等しい」及び「均質」等の物事が等しい状態であることを表す表現は、厳密に等しい状態を表すのみならず、公差、若しくは、同じ機能が得られる程度の差が存在している状態も表すものとする。
　例えば、四角形状や円筒形状等の形状を表す表現は、幾何学的に厳密な意味での四角形状や円筒形状等の形状を表すのみならず、同じ効果が得られる範囲で、凹凸部や面取り部等を含む形状も表すものとする。

　一方、一の構成要素を「備える」、「具える」、「具備する」、「含む」、又は、「有する」という表現は、他の構成要素の存在を除外する排他的な表現ではない。 Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described as the embodiments or shown in the drawings are not intended to limit the scope of the present invention to this, but are merely illustrative. Absent.
For example, a representation representing a relative or absolute arrangement such as “in a direction”, “along a direction”, “parallel”, “orthogonal”, “center”, “concentric” or “coaxial” is strictly Not only does it represent such an arrangement, but also represents a state of relative displacement with an angle or distance that allows the same function to be obtained.
For example, expressions that indicate that things such as "identical", "equal" and "homogeneous" are equal states not only represent strictly equal states, but also have tolerances or differences with which the same function can be obtained. It also represents the existing state.
For example, expressions representing shapes such as quadrilateral shapes and cylindrical shapes not only represent shapes such as rectangular shapes and cylindrical shapes in a geometrically strict sense, but also uneven portions and chamfers within the range where the same effect can be obtained. The shape including a part etc. shall also be expressed.

On the other hand, the expressions "comprising", "having", "having", "including" or "having" one component are not exclusive expressions excluding the presence of other components.
　図１は本発明の一実施形態に係るブレーキシステム１の全体構成を示すブロック図である。
　ブレーキシステム１は、車両の運転席においてオペレータによるブレーキペダル（不図示）の踏み込み力に対して、電動バキュームポンプ７から供給される負圧を倍力源として助勢力を付加するブレーキブースタ３を備えている。ブレーキブースタ３はブレーキペダルの踏み込み力を真空タンク２内に供給された負圧によって増大した後、マスタシリンダ４に伝達することによって助勢力を付加してブレーキＡＳＳＹ５を駆動する。
　尚、真空タンク２内にはブレーキペダルの踏み込みに応じて外気が導入されることによって負圧が消費されるが、該外気の取り込み口にはエアフィルタ６が設けられている。 FIG. 1 is a block diagram showing an entire configuration of a brake system 1 according to an embodiment of the present invention.
The brake system 1 includes a brake booster 3 that applies an assisting force using a negative pressure supplied from the electric vacuum pump 7 as a boosting source with respect to the depression force of a brake pedal (not shown) by the operator at the driver's seat of the vehicle. ing. The brake booster 3 increases the depression force of the brake pedal by the negative pressure supplied into the vacuum tank 2 and then transmits it to the master cylinder 4 to apply an assisting force to drive the brake ASSY 5.
Although negative pressure is consumed by introducing outside air into the vacuum tank 2 according to depression of the brake pedal, an air filter 6 is provided at the outside air intake port.
　真空タンク２には、バッテリ等に蓄えられた電気エネルギーを用いて作動可能な電動バキュームポンプ７が接続されており、該電動バキュームポンプ７の動作に応じて負圧が供給される。図１の例では、真空タンク２を複数のサブタンク２ａ及び２ｂから構成することにより、蓄積可能な負圧容量を大きくすることで、発生可能な制動力を大きくしている。また、このように複数のサブタンク２ａ及び２ｂで真空タンク２を構成することにより、限られたスペース内で大きな負圧容量を確保しつつ、レイアウトの自由度を高めることができる。
　尚、２つのサブタンク２ａ及び２ｂは互いに連通しており、それぞれの真空度が同じになるように構成されている。 The vacuum tank 2 is connected to an electric vacuum pump 7 operable using electric energy stored in a battery or the like, and a negative pressure is supplied according to the operation of the electric vacuum pump 7. In the example of FIG. 1, by configuring the vacuum tank 2 from a plurality of subtanks 2 a and 2 b, the amount of negative pressure capacity that can be accumulated is increased, thereby increasing the braking force that can be generated. Further, by forming the vacuum tank 2 with the plurality of sub tanks 2a and 2b as described above, it is possible to increase the freedom of layout while securing a large negative pressure capacity in a limited space.
The two sub tanks 2a and 2b are in communication with each other, and are configured to have the same degree of vacuum.
　真空タンク２には、所定の真空度で自動的に開閉する圧力スイッチ８が設けられている。第１圧力スイッチ８ａは真空度がＰ１（例えば４５ｋＰａ）以上になると閉状態から開状態に切り換わり、第２圧力スイッチ８ｂは真空度がＰ２（例えば７０ｋＰａ）以上になると閉状態から開状態に切り換わるように設計されている。また第３圧力スイッチ８ｃは真空度がＰ３（例えば３５ｋＰａ）以下になると開状態から閉状態に切り換わるように設計されている。 The vacuum tank 2 is provided with a pressure switch 8 that automatically opens and closes at a predetermined degree of vacuum. The first pressure switch 8a switches from the closed state to the open state when the degree of vacuum reaches P1 (for example 45 kPa) or higher, and the second pressure switch 8b switches from the closed state to the open state when the degree of vacuum exceeds P2 (for example 70 kPa) It is designed to replace it. The third pressure switch 8c is designed to switch from the open state to the closed state when the degree of vacuum becomes P3 (e.g. 35 kPa) or less.
　尚、図１の例では第１圧力スイッチ８ａ及び第２の圧力スイッチ８ｂは、それぞれサブタンク２ａ及び２ｂに取り付けられた場合を示しているが、上述したようにいずれのサブタンクも同じ真空度であるため、第１圧力スイッチ８ａ及び第２圧力スイッチ８ｂをサブタンク２ａに取り付けてもよいし、第１圧力スイッチ８ａ及び第２圧力スイッチ８ｂをサブタンク２ｂに取り付けてもよい。また、第１圧力スイッチ８ａ及び第２圧力スイッチ８ｂをサブタンク２ａ及び２ｂにそれぞれ取り付けることによって、システムの信頼性を向上させてもよい。 In the example shown in FIG. 1, the first pressure switch 8a and the second pressure switch 8b are attached to the sub tanks 2a and 2b respectively, but as described above, all the sub tanks have the same degree of vacuum. Therefore, the first pressure switch 8a and the second pressure switch 8b may be attached to the sub tank 2a, or the first pressure switch 8a and the second pressure switch 8b may be attached to the sub tank 2b. Also, the reliability of the system may be improved by attaching the first pressure switch 8a and the second pressure switch 8b to the sub tanks 2a and 2b, respectively.
　ブザー９はブレーキシステム１において異常が発生した場合に警告音（オペレータの五感によって検知可能なものである範囲において限定されない）を発することによってオペレータに報知する手段である。 The buzzer 9 is a means for notifying the operator by emitting a warning sound (which is not limited in a range detectable by the operator's five senses) when an abnormality occurs in the brake system 1.
　コントローラ１０はブレーキシステム１の動作制御を統括するコントロールユニットである。図１ではコントローラ１０の内部構成を機能ブロックとして示しており、電動バキュームポンプ７を制御するポンプ制御手段１３、第１圧力スイッチ及び第２圧力スイッチの開閉状態に基づいてブレーキブースタ３における真空度を検出する真空度検出手段１４、電動バキュームポンプ７の連続運転時間を計測する連続運転時間計測手段１５、及び、ブザー９ｂの動作を制御する警告出力手段１６を含んで構成されている。 The controller 10 is a control unit that controls the operation control of the brake system 1. FIG. 1 shows the internal configuration of the controller 10 as a functional block, and the degree of vacuum in the brake booster 3 is determined based on the pump control means 13 for controlling the electric vacuum pump 7, and the open and closed states of the first pressure switch and the second pressure switch. The apparatus comprises a vacuum degree detecting means 14 for detecting, a continuous operating time measuring means 15 for measuring the continuous operating time of the electric vacuum pump 7, and a warning output means 16 for controlling the operation of the buzzer 9b.
　図２はブレーキシステム１の駆動回路を示す模式図である。
　コントローラ１０は端子１０ａ乃至１０ｆを有しており、各端子にて授受される電気信号に基づいて電動バキュームポンプ７の動作制御が実施される。
　端子１０ａは高電位線１１（＋１２Ｖ）に接続されており、コントローラ１０の駆動用電力が入力される。
　端子１０ｂ及び端子１０ｃは、それぞれ第１圧力スイッチ８ａ及び第２圧力スイッチ８ｂを介して高電位線１１に接続されている。第１圧力スイッチ８ａ及び第２圧力スイッチ８ｂは初期状態において閉状態に設定されており、真空タンク２の真空度がそれぞれの閾値未満に達すると開状態に切り換わる。すると、端子１０ｂ及び端子１０ｃは高電位線１１に短絡される。このように、コントローラ１０は端子１０ｂ及び端子１０ｃにおける電位検知に基づいて、第１圧力スイッチ８ａ及び第２圧力スイッチ８ｂの開閉状態が把握できるようになっている。
　尚、端子１０ｄは接地端子である。 FIG. 2 is a schematic view showing a drive circuit of the brake system 1.
The controller 10 has terminals 10a to 10f, and the operation control of the electric vacuum pump 7 is carried out based on the electric signals transmitted and received at each terminal.
The terminal 10 a is connected to the high potential line 11 (+12 V), and the driving power of the controller 10 is input.
The terminal 10b and the terminal 10c are connected to the high potential line 11 via the first pressure switch 8a and the second pressure switch 8b, respectively. The first pressure switch 8a and the second pressure switch 8b are set in the closed state in the initial state, and are switched to the open state when the degree of vacuum of the vacuum tank 2 reaches less than the respective threshold values. Then, the terminals 10 b and 10 c are shorted to the high potential line 11. Thus, the controller 10 can grasp the open / close state of the first pressure switch 8a and the second pressure switch 8b based on the potential detection at the terminal 10b and the terminal 10c.
The terminal 10d is a ground terminal.
　端子１０ｅにはブザー９ｂが接続されており、当該接続ラインを介してコントローラ１０から入力される制御信号に従って、ブザー９のＯＮ／ＯＦＦが行われる。
　端子１０ｆには電動バキュームポンプ７をＯＮ／ＯＦＦするための制御リレー１２が接続されている。コントローラ１０は端子１０ｆから電動バキュームポンプ７の制御信号（制御電流）を出力し、当該端子１０ｆに接続された制御リレー１２のコイル部１２ａを励磁されることによってスイッチ１２ｂがＯＮ／ＯＦＦ切換制御される。制御リレー１２がＯＮされると、電動バキュームポンプ７に高電位線１１から駆動用の電力が供給され、始動する。 A buzzer 9b is connected to the terminal 10e, and the buzzer 9 is turned on / off in accordance with a control signal input from the controller 10 via the connection line.
A control relay 12 for turning on / off the electric vacuum pump 7 is connected to the terminal 10f. The controller 10 outputs a control signal (control current) of the electric vacuum pump 7 from the terminal 10f, and the switch 12b is controlled to be switched ON / OFF by exciting the coil portion 12a of the control relay 12 connected to the terminal 10f. Ru. When the control relay 12 is turned on, electric power for driving is supplied to the electric vacuum pump 7 from the high potential line 11, and the electric vacuum pump 7 is started.
　ブザー９ａは、第３圧力スイッチ８ｃを介して高電位線１１に接続されている。第３圧力スイッチ８ｃは初期状態において開状態に設定されており、真空タンク２の真空度がそれぞれの閾値以下に達すると閉状態に切り換わる。 The buzzer 9a is connected to the high potential line 11 via the third pressure switch 8c. The third pressure switch 8c is set to an open state in the initial state, and switches to a closed state when the degree of vacuum of the vacuum tank 2 reaches the respective threshold value or less.
　図３は電動バキュームポンプ７を動作に伴う真空タンク２の真空度Ｐの時間推移を示すグラフである。
　時刻０で電動バキュームポンプ７が始動すると、真空タンク２の真空度Ｐは増加する（ここで真空度が増加するというのは、負圧が増加する意味である）。図３に示す閾値Ｐ１はブレーキペダルに十分な助勢力を付加するために必要な真空度の下限値として規定されたものであり、例えば法定基準で要求される制動力を発生させるために必要な真空度に、安全のための一定のマージンを持って規定したものである。
　真空度Ｐは時間に対して対数的に増加しており、ある程度時間が経過すると真空度Ｐはある一定値に向かって収束する。このように電動バキュームポンプ７の負圧供給効率は、真空タンク２の真空度Ｐが高くなると低くなる傾向にあり、図３に示す閾値Ｐ２は良好な負圧供給効率が得られる範囲の上限真空度として規定されたものであり、例えば収束値の７０％程度の値を採用するとよい。
　尚、後述するように本実施例にかかるブレーキシステム１では、電動バキュームポンプ７がＰ１＜Ｐ＜Ｐ２の範囲で作動するように制御されるが、この範囲はオペレータがブレーキペダルを複数回操作可能な幅が確保できる程度に設定するとよいが、具体的には電動バキュームポンプの特性等を考慮して決定するとよい。 FIG. 3 is a graph showing the time course of the degree of vacuum P of the vacuum tank 2 as the electric vacuum pump 7 is operated.
When the electric vacuum pump 7 is started at time 0, the degree of vacuum P of the vacuum tank 2 increases (here, the increase in degree of vacuum means that the negative pressure increases). The threshold value P1 shown in FIG. 3 is defined as the lower limit value of the degree of vacuum necessary to apply a sufficient assisting force to the brake pedal, and is required, for example, to generate the braking force required by the legal standard. The degree of vacuum is defined with a certain margin for safety.
The degree of vacuum P increases logarithmically with time, and after a certain amount of time passes, the degree of vacuum P converges toward a certain constant value. Thus, the negative pressure supply efficiency of the electric vacuum pump 7 tends to become lower as the vacuum degree P of the vacuum tank 2 becomes higher, and the threshold P2 shown in FIG. 3 is the upper limit vacuum in the range where good negative pressure supply efficiency can be obtained. For example, a value of about 70% of the convergence value may be adopted.
As described later, in the brake system 1 according to this embodiment, the electric vacuum pump 7 is controlled to operate in the range of P1 <P <P2, but in this range, the operator can operate the brake pedal multiple times. It is preferable to set to such an extent that a certain width can be secured, but specifically, it may be determined in consideration of the characteristics of the electric vacuum pump and the like.
　図４はコントローラ１０によるブレーキシステム１の制御内容を示すフローチャートである。
　まずコントローラ１０（真空度検出手段１４）は、第２圧力スイッチ８ｂが閉状態であるか否かを判断する（ステップＳ１０１）。上述したように、第２圧力スイッチ８ｂは真空タンク２の真空度Ｐが閾値Ｐ２以上である場合に開状態に切り換わるため、ステップＳ１０１では実質的に真空度Ｐが閾値Ｐ２より低いか否かを判定することができる。
　第２圧力スイッチ８ｂが閉状態であると判定した場合（ステップＳ１０１：ＹＥＳ）、コントローラ１０（真空度検出手段１４）は更に、第１圧力スイッチ８ａが閉状態であるか否かを判断する（ステップＳ１０２）。上述したように、第１圧力スイッチ８ａは真空タンク２の真空度Ｐが閾値Ｐ１以上である場合に開状態に切り換わるため、ステップＳ１０２では実質的に真空度Ｐが閾値Ｐ１以下であるか否かを判定することができる。
　このようにステップＳ１０１及びステップ１０２では、第１圧力スイッチ８ａ及び第２圧力スイッチ８ｂの開閉状態を検出することによって、真空タンク２の真空度Ｐが適切な範囲（Ｐ１＜Ｐ＜Ｐ２）にあるか否かを判定するロジックが形成されている。 FIG. 4 is a flowchart showing the control contents of the brake system 1 by the controller 10.
First, the controller 10 (vacuum degree detection means 14) determines whether the second pressure switch 8b is in the closed state (step S101). As described above, since the second pressure switch 8b is switched to the open state when the degree of vacuum P of the vacuum tank 2 is the threshold P2 or more, whether or not the degree of vacuum P is substantially lower than the threshold P2 in step S101 Can be determined.
When it is determined that the second pressure switch 8b is in the closed state (step S101: YES), the controller 10 (vacuum degree detection means 14) further determines whether or not the first pressure switch 8a is in the closed state ( Step S102). As described above, since the first pressure switch 8a is switched to the open state when the vacuum degree P of the vacuum tank 2 is equal to or higher than the threshold value P1, in step S102 the vacuum degree P is substantially equal to or lower than the threshold value P1. Can be determined.
Thus, in steps S101 and 102, the degree of vacuum P of the vacuum tank 2 is in an appropriate range (P1 <P <P2) by detecting the open / close states of the first pressure switch 8a and the second pressure switch 8b. Logic is formed to determine whether or not.
　第１圧力スイッチ８ａが閉状態であると判定した場合（ステップＳ１０２：ＹＥＳ）、コントローラ１０は真空度ＰがＰ≦Ｐ１の範囲、すなわち真空度Ｐが下限値以下に低下しているため、コントローラ１０はポンプ制御手段１３において以下の制御を実施することで電動バキュームポンプ７を始動し、負圧供給を開始する。 If it is determined that the first pressure switch 8a is in the closed state (step S102: YES), the controller 10 determines that the degree of vacuum P is in the range of P ≦ P1, that is, the degree of vacuum P is below the lower limit. 10 performs the following control in the pump control means 13 to start the electric vacuum pump 7 and start negative pressure supply.
　まずコントローラ１０は制御リレー１２がＯＦＦであるか否かについて、端子１０ｆから出力される制御電流値をモニタすることによって判断する（ステップＳ１０３）。制御リレー１２がＯＦＦである場合（ステップＳ１０３：ＹＥＳ）、コントローラ１０は端子１０ｆから制御電流を出力して制御リレーをＯＮして電動バキュームポンプ７を始動すると共に、電動バキュームポンプ７の連続運転時間Ｔの計測を開始する（ステップＳ１０４）。 First, the controller 10 determines whether the control relay 12 is OFF or not by monitoring the value of the control current output from the terminal 10f (step S103). When the control relay 12 is OFF (step S103: YES), the controller 10 outputs a control current from the terminal 10f to turn on the control relay to start the electric vacuum pump 7, and the continuous operation time of the electric vacuum pump 7 Measurement of T is started (step S104).
　このように真空度Ｐが下限値以下になると、電動バキュームポンプ７を始動してブレーキブースタ３に負圧供給することでブレーキシステム１の制動力を適切な範囲に管理することができる。また、電動バキュームポンプ７の作動開始と共に、連続運転時間計測手段１５において連続運転時間Ｔの計測を開始することで、電動バキュームポンプ７の動作期間を短縮すると共に、頻繁に電動バキュームポンプ７がＯＮ／ＯＦＦされることを防止し，ポンプ寿命を長期化できる。
　尚、所定時間Ｔ１の設定例としては、オペレータによるブレーキペダルの踏み込み動作が少なくとも１回行われつつ、電動バキュームポンプ７によって真空度を閾値Ｐ１からＰ２に増加させるのに必要な期間として設定するとよい。 As described above, when the vacuum degree P becomes lower than the lower limit value, the electric vacuum pump 7 is started to supply a negative pressure to the brake booster 3 so that the braking force of the brake system 1 can be managed in an appropriate range. Further, by starting measurement of the continuous operation time T in the continuous operation time measuring means 15 at the same time when the operation of the electric vacuum pump 7 is started, the operation period of the electric vacuum pump 7 is shortened and the electric vacuum pump 7 is frequently turned on. This prevents the pump from being turned off and prolongs the pump life.
As a setting example of the predetermined time T1, it may be set as a period necessary for increasing the degree of vacuum from the threshold value P1 to the threshold value P2 by the electric vacuum pump 7 while the depression operation of the brake pedal by the operator is performed at least once. .
　ステップＳ１０３において既に制御リレー１２がＯＮされていた場合には（ステップＳ１０３：ＮＯ）、連続運転時間計測手段１５における計測結果に基づいて、電動バキュームポンプ７の連続運転時間Ｔが所定時間Ｔ１に達しているか否かを判定する（ステップＳ１０５）。連続運転時間Ｔが所定時間Ｔ１に達していない場合（ステップＳ１０５：ＹＥＳ）、コントローラ１０は処理をステップＳ１０４に戻し、電動バキュームポンプ７の作動と連続運転時間計測手段１５による連続運転時間Ｔの計測を継続する。
　その後、ステップＳ１０５において連続運転時間Ｔが所定時間Ｔ１に達したと判定された場合（ステップＳ１０５：ＮＯ）、コントローラ１０は制御リレー１２をＯＦＦに切り換えることにより電動バキュームポンプ７を停止させると共に、連続運転時間Ｔの計測を初期化する（ステップＳ１０６）。 If the control relay 12 has already been turned on in step S103 (step S103: NO), the continuous operation time T of the electric vacuum pump 7 reaches the predetermined time T1 based on the measurement result of the continuous operation time measuring means 15 It is determined whether or not (step S105). If the continuous operation time T has not reached the predetermined time T1 (step S105: YES), the controller 10 returns the process to step S104, and the operation of the electric vacuum pump 7 and the measurement of the continuous operation time T by the continuous operation time measuring means 15 To continue.
Thereafter, when it is determined in step S105 that the continuous operation time T has reached the predetermined time T1 (step S105: NO), the controller 10 switches the control relay 12 to OFF to stop the electric vacuum pump 7 and continuously The measurement of the operating time T is initialized (step S106).
　尚、ステップＳ１０６のように連続運転時間Ｔが，電動バキュームポンプ７を停止する所定時間Ｔ１に達したにも関わらず，真空度Ｐが下限値Ｐ１未満の場合、その旨をオペレータに報知するためのエラー信号を出力する。エラー信号は，連続運転時間Ｔが所定時間Ｔ１に達したことをオペレータに報知するためのもので，ブザー９ｂを作動させることによってオペレータに報知する。なお、オペレータの視界に入る位置に設けられたランプを作動させても良い。 If the degree of vacuum P is less than the lower limit value P1 despite notifying that the continuous operation time T has reached the predetermined time T1 for stopping the electric vacuum pump 7 as in step S106, the operator is notified of that effect. Output an error signal of The error signal is for notifying the operator that the continuous operation time T has reached the predetermined time T1, and is notified to the operator by operating the buzzer 9b. Note that a lamp provided at a position within the field of view of the operator may be operated.
　一方、ステップＳ１０１において第２圧力スイッチ８ｂが開状態であると判定した場合（ステップＳ１０１：ＮＯ）、コントローラ１０は真空度ＰがＰ２＜Ｐの範囲、すなわち真空度Ｐが高いために電動バキュームポンプ７の負圧供給効率十分に得られない範囲（図３を参照）にあると判断し、ポンプ制御手段１３によって制御リレー１２をＯＦＦすることにより、電動バキュームポンプ７を停止する（ステップＳ１０７）。このとき、連続運転時間Ｔの計測も初期化される。 On the other hand, when it is determined in step S101 that the second pressure switch 8b is in the open state (step S101: NO), the controller 10 controls the vacuum degree P in the range of P2 <P, that is, the vacuum degree P is high. It is determined that the negative pressure supply efficiency 7 is not sufficiently obtained (see FIG. 3), and the control relay 12 is turned off by the pump control means 13 to stop the electric vacuum pump 7 (step S107). At this time, the measurement of the continuous operation time T is also initialized.
　またステップＳ１０２において第１圧力スイッチ８ａが開状態であると判定した場合（ステップＳ１０２：ＮＯ）、コントローラ１０（真空度検出手段１４）は真空度ＰがＰ１＜Ｐ＜Ｐ２の範囲にあると判断する。この場合、コントローラ１０は制御リレー１２がＯＦＦであるか否かを判定することにより、電動バキュームポンプ７の動作状態を確認する（ステップＳ１０８）。制御リレー１２がＯＦＦである場合（ステップＳ１０８：ＹＥＳ）、電動バキュームポンプ７の停止状態を継続すると共に連続運転時間Ｔを初期化する（ステップＳ１０９）。 When it is determined in step S102 that the first pressure switch 8a is in the open state (step S102: NO), the controller 10 (vacuum degree detection unit 14) determines that the vacuum degree P is in the range of P1 <P <P2. Do. In this case, the controller 10 determines whether the control relay 12 is off, thereby confirming the operating state of the electric vacuum pump 7 (step S108). If the control relay 12 is OFF (step S108: YES), the stop state of the electric vacuum pump 7 is continued and the continuous operation time T is initialized (step S109).
　ステップＳ１０８において制御リレー１２がＯＮである場合（ステップＳ１０８：ＮＯ）、コントローラ１０は、計測した連続運転時間Ｔが所定時間Ｔ１に達したか否かを判定する（ステップＳ１１０）。連続運転時間Ｔが所定時間Ｔ１に達していない場合（ステップＳ１１０：ＹＥＳ）、コントローラ１０は電動バキュームポンプ７の動作及び連続運転時間Ｔの積算を継続する（ステップＳ１１１）。
　その後、連続運転時間Ｔが所定時間Ｔ１に達すると（ステップＳ１１０：ＮＯ）、コントローラ１０は制御リレー１２をＯＦＦすることにより電動バキュームポンプ７を停止すると共に連続運転時間Ｔを初期化する（ステップＳ１１２）。 When the control relay 12 is ON at step S108 (step S108: NO), the controller 10 determines whether the measured continuous operation time T has reached a predetermined time T1 (step S110). If the continuous operation time T has not reached the predetermined time T1 (step S110: YES), the controller 10 continues the operation of the electric vacuum pump 7 and the integration of the continuous operation time T (step S111).
Thereafter, when the continuous operation time T reaches the predetermined time T1 (step S110: NO), the controller 10 turns off the control relay 12 to stop the electric vacuum pump 7 and initialize the continuous operation time T (step S112). ).
　図５は本発明の一実施形態に係るブレーキシステム１の動作時における真空タンク２の真空度Ｐの推移を示すグラフである。尚、図５ではオペレータによるブレーキペダルの操作状態を下段に示している。
　真空度Ｐはブレーキペダルが踏み込まれる毎に真空タンク２に外気が導入されることによって略階段状に低下する。そして真空度Ｐが閾値Ｐ１に達すると電動バキュームポンプ７が始動し、真空タンク２への負圧供給が開始される（図４のステップＳ１０４）。その後、仮にブレーキペダルの踏み込みがない場合には真空度Ｐは対数的に増加するが（図３を参照）、図５では電動バキュームポンプ７の作動中にもブレーキペダルの踏み込みが行われているため、パルス状の波形で増加している。そして真空度が閾値Ｐ２に達すると電動バキュームポンプ７が停止する（図４のステップＳ１０７を参照）。
　また，真空度Ｐが閾値Ｐ３に達するとブザー９ａが始動される。 FIG. 5 is a graph showing the transition of the degree of vacuum P of the vacuum tank 2 at the time of operation of the brake system 1 according to an embodiment of the present invention. In FIG. 5, the operation state of the brake pedal by the operator is shown in the lower part.
The degree of vacuum P is lowered substantially in a step-like manner by the introduction of external air into the vacuum tank 2 each time the brake pedal is depressed. When the degree of vacuum P reaches the threshold value P1, the electric vacuum pump 7 is started, and the negative pressure supply to the vacuum tank 2 is started (step S104 in FIG. 4). Thereafter, if the brake pedal is not depressed, the degree of vacuum P increases logarithmically (see FIG. 3), but in FIG. 5, the brake pedal is depressed even while the electric vacuum pump 7 is operating. Because of this, it has a pulse-like waveform. When the degree of vacuum reaches the threshold P2, the electric vacuum pump 7 is stopped (see step S107 in FIG. 4).
Further, when the degree of vacuum P reaches the threshold value P3, the buzzer 9a is started.
　なお、ブザー９ａの始動条件となる閾値Ｐ３は、複数ある法定基準のうち、最も厳しい法定基準で要求される制動力を発生させるために必要な真空度に設定しても良い。たとえば、最も厳しい法定基準で要求される制動力を発生させるために必要な真空度は、法定基準で要求される制動力を発生させるために必要な真空度に一定のマージンを持って規定された閾値Ｐ１よりも、一定のマージン分低い値となる。この一定のマージンは、コントローラ１０からの指令から電動バキュームポンプ７の作動までの間に一瞬の遅れがあっても、最も厳しい法定基準で要求される制動力を下回らないように設定される。 The threshold value P3 which is the starting condition of the buzzer 9a may be set to a degree of vacuum required to generate the braking force required by the strictest legal standard among a plurality of legal standards. For example, the degree of vacuum required to generate the braking force required by the strictest legal standards was defined with a certain margin to the degree of vacuum required to generate the braking force required by legal standards. The value is lower by a certain margin than the threshold value P1. This constant margin is set so as not to fall below the braking force required by the strictest legal standard even if there is a momentary delay between the command from the controller 10 and the operation of the electric vacuum pump 7.
　図６は本発明の一実施形態に係るブレーキシステム１の動作時における真空度Ｐの推移の他の例を示すグラフである。図６では図５の場合に比べて電動バキュームポンプ７の作動中におけるブレーキペダルの踏み込み量が大きい場合を示している。
　この例では、ブレーキペダルの踏み込みによって真空度Ｐが閾値Ｐ１に達すると、図５と同様に電動バキュームポンプ７が作動し、その後もブレーキペダルの踏み込みタイミングに応じてパルス状に真空度が増加する。上述したように図６ではブレーキペダルの踏み込み量が大きいため、真空度が閾値Ｐ２に達する前に連続運転時間Ｔが所定時間Ｔ１に達することによって、電動バキュームポンプが停止される（図４のステップＳ１１０を参照）。 FIG. 6 is a graph showing another example of the transition of the degree of vacuum P when the brake system 1 according to the embodiment of the present invention is in operation. FIG. 6 shows a case where the depression amount of the brake pedal during the operation of the electric vacuum pump 7 is larger than that in the case of FIG.
In this example, when the degree of vacuum P reaches the threshold value P1 due to depression of the brake pedal, the electric vacuum pump 7 operates as in FIG. 5, and thereafter the degree of vacuum increases in a pulse according to the depression timing of the brake pedal. . As described above, since the depression amount of the brake pedal is large in FIG. 6, the electric vacuum pump is stopped when the continuous operation time T reaches the predetermined time T1 before the vacuum degree reaches the threshold value P2 (step in FIG. 4) See S110).
　図７は本発明の一実施形態に係るブレーキシステム１に異常が発生した場合における真空度Ｐの推移を示すグラフである。図７では異常検知によるブザー９ｂの作動状態を併せて示している。
　この例では、ブレーキペダルの踏み込みによって真空度Ｐが閾値Ｐ１に達すると、図５と同様に電動バキュームポンプ７が作動するものの、真空タンク２の真空度Ｐは上昇しておらず、閾値Ｐ１未満の状態が所定時間Ｔ１継続している。このような場合、電動バキュームポンプ７の故障や真空タンク２の漏れのような異常が存在する可能性が高く、コントローラ１０の警告出力手段１６はブザー９ｂを作動させることによってオペレータに報知する。尚、警告出力手段１６は、オペレータの視界に入る位置に設けられたランプを作動させても良い（図４のステップＳ１０６を参照）。 FIG. 7 is a graph showing transition of the degree of vacuum P when an abnormality occurs in the brake system 1 according to an embodiment of the present invention. FIG. 7 also shows the operating state of the buzzer 9b due to the detection of an abnormality.
In this example, when the vacuum degree P reaches the threshold value P1 by the depression of the brake pedal, the electric vacuum pump 7 operates as in FIG. 5, but the vacuum degree P of the vacuum tank 2 does not increase and is less than the threshold value P1. State continues for a predetermined time T1. In such a case, there is a high possibility that there is an abnormality such as a failure of the electric vacuum pump 7 or a leak of the vacuum tank 2, and the warning output means 16 of the controller 10 notifies the operator by operating the buzzer 9b. Note that the warning output means 16 may operate a lamp provided at a position that is within the field of view of the operator (see step S106 in FIG. 4).
　以上説明したように、本発明の少なくとも一実施形態に係るブレーキシステム１によれば、真空度Ｐ及び連続運転時間Ｔを制御パラメータとして、いずれか一方が所定の閾値に達したタイミングで電動バキュームポンプ７を停止させる。真空度Ｐが閾値Ｐ２より大きくなった場合に電動バキュームポンプ７を停止すると、電動バキュームポンプ７の動作範囲を真空度が比較的低い範囲に限定できるので、良好な負圧供給効率が得られると共に、ポンプ負荷が少ない領域で動作できるのでポンプ寿命を長期化することができる。また、連続運転時間Ｔが所定期間Ｔ１より長くなった場合に電動バキュームポンプ７を停止すると、電動バキュームポンプ７の動作期間を効率的に短縮することで、ポンプ寿命を長期化することができる。これにより、産業車両等の比較的大型の車両においても、比較的容量の小さい電動バキュームポンプを用いることができ、コストダウン・ブレーキシステムの小型化・省スペース化を図ることができる。このように本発明の少なくとも一実施形態では、電動バキュームポンプ７の負圧供給能力の向上とポンプ寿命の長期化を両立可能なブレーキシステムを実現することができる。
　また、電動式バキュームポンプは電気的エネルギーで動作可能であるため、エンジンの動力によって駆動される機械式バキュームポンプのように常時ＯＮである必要がないため効率が高く、配線の脱着等によって容易に後付けできるので、レイアウト上の自由度も高い。また電気的に制御可能であるため、制御性にも優れている。 As described above, according to the brake system 1 according to at least one embodiment of the present invention, the electric vacuum pump is operated at a timing when one of the vacuum degree P and the continuous operation time T has reached a predetermined threshold value. Stop 7 If the electric vacuum pump 7 is stopped when the degree of vacuum P becomes larger than the threshold P2, the operating range of the electric vacuum pump 7 can be limited to a range where the degree of vacuum is relatively low, so that a good negative pressure supply efficiency can be obtained. Since the pump load can be operated in a low area, the pump life can be extended. Further, when the electric vacuum pump 7 is stopped when the continuous operation time T becomes longer than the predetermined period T1, the pump life can be extended by effectively shortening the operation period of the electric vacuum pump 7. As a result, even in a relatively large vehicle such as an industrial vehicle, the electric vacuum pump having a relatively small capacity can be used, and the cost reduction and the reduction in size and space saving of the brake system can be achieved. As described above, in at least one embodiment of the present invention, it is possible to realize a brake system capable of achieving both the improvement of the negative pressure supply capability of the electric vacuum pump 7 and the prolongation of the pump life.
In addition, since the electric vacuum pump can be operated with electrical energy, it is not necessary to always be on like the mechanical vacuum pump driven by the power of the engine, so the efficiency is high and it is easy by removing the wiring. Since it can be retrofitted, it has a high degree of freedom in layout. Moreover, since it can be controlled electrically, it is excellent in controllability.
　このように上記ブレーキシステム１では電動バキュームポンプ７の負圧供給能力を向上すると共に長いポンプ寿命を達成できるので、一般車両（乗用車等）に比べて車重の重い産業車両への搭載が可能となる。 As described above, since the brake system 1 can improve the negative pressure supply capacity of the electric vacuum pump 7 and achieve a long pump life, it can be mounted on a heavy industrial vehicle as compared to a general vehicle (such as a passenger car). Become.
　本発明の少なくとも一実施形態はバキュームポンプからの供給負圧を利用して、オペレータによるブレーキ操作力に助勢力を付加するブレーキシステム及びブレーキ制御方法に利用可能である。 At least one embodiment of the present invention can be used for a brake system and a brake control method that apply an assisting force to a brake operating force by an operator using a negative pressure supplied from a vacuum pump.
　　１　ブレーキシステム
　　２　真空タンク
　　３　ブレーキブースタ
　　４　マスタシリンダ
　　５　ブレーキＡＳＳＹ
　　６　エアフィルタ
　　７　電動バキュームポンプ
　　８　圧力スイッチ
　　９　ブザー（又はランプ）
　１０　コントローラ
　１１　高電位線
　１２　制御リレー
　１３　ポンプ制御手段
　１４　真空度検出手段
　１５　連続運転時間計測手段
　１６　警告出力手段 1 brake system 2 vacuum tank 3 brake booster 4 master cylinder 5 brake ASSY
6 Air filter 7 Electric vacuum pump 8 Pressure switch 9 Buzzer (or lamp)
DESCRIPTION OF SYMBOLS 10 controller 11 high potential line 12 control relay 13 pump control means 14 vacuum degree detection means 15 continuous operation time measuring means 16 warning output means

Claims (11)

  1. 　オペレータによるブレーキ操作力を補助するように構成されたブレーキブースタと、
    　前記ブレーキブースタに負圧を供給するように構成された電動バキュームポンプと、
    　前記ブレーキブースタにおける真空度を検出するように構成された真空度検出手段と、
    　前記電動バキュームポンプの連続運転時間を計測するように構成された連続運転時間計測手段と、
    　前記真空度検出手段によって検出された真空度、及び、前記連続運転時間計測手段によって計測された連続運転時間に基づいて、前記電動バキュームポンプを制御するように構成されたポンプ制御手段と
    を備えるブレーキシステムであって、
    　前記ポンプ制御手段は、前記真空度が予め設定された所定上限値より大きくなった場合と、前記連続運転時間が予め設定された所定時間より長くなった場合とのいずれか早い方のタイミングで、前記電動バキュームポンプを停止させるように構成されたことを特徴とするブレーキシステム。     A brake booster configured to assist the brake operating force by the operator;
    An electric vacuum pump configured to supply a negative pressure to the brake booster;
    Vacuum degree detection means configured to detect the degree of vacuum in the brake booster;
    Continuous operation time measuring means configured to measure the continuous operation time of the electric vacuum pump;
    A brake comprising: a pump control unit configured to control the electric vacuum pump based on the degree of vacuum detected by the degree of vacuum detection unit and the continuous operation time measured by the continuous operation time measurement unit A system,
    The pump control means is operated at one of the earlier timing when the degree of vacuum becomes larger than a predetermined upper limit value or when the continuous operation time becomes longer than the predetermined period. A brake system configured to stop the electric vacuum pump.
  2. 　前記ポンプ制御手段は、前記真空度が予め設定された所定下限値未満になった時に、前記電動バキュームポンプを作動させると共に、前記連続運転時間計測手段による前記連続運転時間の計測を開始させるように構成されたことを特徴とする請求項１に記載のブレーキシステム。 The pump control means operates the electric vacuum pump and starts measurement of the continuous operation time by the continuous operation time measurement means when the degree of vacuum becomes less than a predetermined lower limit value set in advance. The brake system according to claim 1, characterized in that it is configured.
  3. 　前記連続運転時間計測手段によって計測された前記連続運転時間が前記所定時間以上に達した際に、前記真空度が前記所定下限値未満である場合、警告を出力するように構成された警告出力手段を備えたとことを特徴とする請求項２に記載のブレーキシステム。 Warning output means configured to output a warning when the vacuum degree is less than the predetermined lower limit when the continuous operation time measured by the continuous operation time measuring means reaches the predetermined time or more The brake system according to claim 2, comprising:
  4. 　前記電動バキュームポンプと前記ブレーキブースタとの間に、前記電動バキュームポンプから供給された負圧を蓄えるように構成された複数の真空タンクを有することを特徴とする請求項１から３のいずれか一項に記載のブレーキシステム。 A plurality of vacuum tanks configured to store negative pressure supplied from the electric vacuum pump are provided between the electric vacuum pump and the brake booster according to any one of claims 1 to 3. Brake system according to paragraph.
  5. 　前記複数の真空タンクの各々は、真空度が同じになるように連通されていることを特徴とする請求項４に記載のブレーキシステム。 The brake system according to claim 4, wherein each of the plurality of vacuum tanks is communicated so as to have the same degree of vacuum.
  6. 　前記複数の真空タンクの内の少なくとも一つの真空タンクに取り付けられた、前記真空タンクの真空度が前記所定上限値以上になると閉状態から開状態に切り替わるように構成された第１圧力スイッチと、
    　前記複数の真空タンクの内の少なくとも一つの真空タンクに取り付けられた、前記真空タンクの真空度が前記所定下限値以下になると閉状態から開状態に切か替わるように構成された第２圧力スイッチと、をさらに備え、
    　前記真空度検出手段は、前記第１圧力スイッチおよび前記第２圧力スイッチの開閉状態に基づいて前記ブレーキブースタにおける真空度を検出するように構成されていることを特徴とする請求項５に記載のブレーキシステム。     A first pressure switch attached to at least one vacuum tank of the plurality of vacuum tanks, the first pressure switch being configured to switch from the closed state to the open state when the degree of vacuum of the vacuum tank reaches or exceeds the predetermined upper limit;
    A second pressure switch attached to at least one vacuum tank of the plurality of vacuum tanks, configured to switch from the closed state to the open state when the degree of vacuum of the vacuum tank falls below the predetermined lower limit value. And further,
    The said vacuum degree detection means is comprised so that the vacuum degree in the said brake booster may be detected based on the opening / closing state of a said 1st pressure switch and a said 2nd pressure switch. Brake system.
  7. 　前記第１圧力スイッチおよび前記第２圧力スイッチは、前記複数の真空タンクの各々に夫々取り付けられていることを特徴とする請求項６に記載のブレーキシステム。 The brake system according to claim 6, wherein the first pressure switch and the second pressure switch are respectively attached to the plurality of vacuum tanks.
  8. 　請求項１から７のいずれか一項に記載のブレーキシステムを備えることを特徴とする産業車両。 An industrial vehicle comprising the brake system according to any one of claims 1 to 7.
  9. 　オペレータによるブレーキ操作力を補助するブレーキブースタにおける真空度を検出する工程と、
    　前記ブレーキブースタに負圧を供給する電動バキュームポンプの連続運転時間を計測する工程と、
    　前記真空度が予め設定された所定上限値より大きくなったと、前記連続運転時間が予め設定された所定時間より長くなった場合とのいずれか早い方のタイミングで、前記電動バキュームポンプを停止させる工程と、を備えることを特徴とするブレーキ制御方法。     Detecting the degree of vacuum in the brake booster which assists the brake operating force by the operator;
    Measuring a continuous operation time of an electric vacuum pump for supplying a negative pressure to the brake booster;
    A step of stopping the electric vacuum pump at a timing, whichever earlier, when the degree of vacuum becomes larger than a predetermined upper limit value or when the continuous operation time becomes longer than the predetermined period, which is previously set And a brake control method characterized by comprising.
  10. 　前記真空度が予め設定された所定下限値未満になった時に、前記電動バキュームポンプを作動させると共に、前記連続運転時間の計測を開始する工程をさらに備えることを特徴とする請求項９に記載のブレーキ制御方法。 10. The method according to claim 9, further comprising the step of operating the electric vacuum pump and starting measurement of the continuous operation time when the degree of vacuum falls below a predetermined lower limit value set in advance. Brake control method.
  11. 　前記連続運転時間が前記所定時間以上に達した際に、前記真空度が前記所定下限値未満である場合に警告を出力する工程をさらに備えることを特徴とする請求項１０に記載のブレーキ制御方法。 The brake control method according to claim 10, further comprising the step of outputting a warning when the degree of vacuum is less than the predetermined lower limit when the continuous operation time reaches the predetermined time or more. .
PCT/JP2014/069885 2014-07-29 2014-07-29 Brake system and brake control method WO2016016937A1 (en)

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CN109733365A (en) * 2019-02-21 2019-05-10 上海拓绅汽车电子有限公司 A kind of control system of the electric vacuum pump for electric car
JP7362818B2 (en) 2022-03-22 2023-10-17 本田技研工業株式会社 gas separation equipment

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CN109733365A (en) * 2019-02-21 2019-05-10 上海拓绅汽车电子有限公司 A kind of control system of the electric vacuum pump for electric car
JP7362818B2 (en) 2022-03-22 2023-10-17 本田技研工業株式会社 gas separation equipment

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