GB2137308A - Rolling control apparatus for an engine; controlling dampers - Google Patents

Abstract

A casing 46, 47 accommodating a liquid is divided by a partitioning disc 41 into two sections. The partitioning disc 41 is secured to one of an engine body or a vehicle chassis, and the walls of the two sections facing the partitioning disc are secured to the other of the engine body or vehicle chassis. The partitioning disc 41 is provided with an orifice mechanism 48, 50, 59 which allows the two sections to communicate with each other. When the rate of change of the accelerator pedal angle exceeds a predetermined value, the orifice mechanism 48, 50, 59 is controlled to restrict the communication between the two sections to increase the damping action, whereby the rolling of the engine body is prevented. The orifice mechanism comprises a rotary valve 50 which is either open or closed and a permanently open path 59. Other parameters which may be sensed and used to control the valve are accelerator pedal angle, engine revolutions and gear change. <IMAGE>

Description

SPECIFICATION Rolling control apparatus for an engine This invention relates to a rolling control apparatus for an engine, which can electronically control and suppress the rolling of an automobile engine.

In an automobile in which the engine is mounted horizontally, the engine is subject to great rolling due to the reaction against its torque. In order to prevent the engine from striking the walls of the engine room and various pipings and components therein, shock absorbers called rolling stoppers are provided. The rolling stopper is of a structure in which an arm extending from the engine is in contact with a bracket provided on the vehicle body.

With the prior art rolling stopper, however, the arm strikes the bracket due to the reaction against the engine torque, and the shock is transmitted to the vehicle body and deteriorates the comfortability. Some of the rolling stoppers are made of soft rubber to be able to absorb even the slight vibrations of the engine generated during a normal run. In this case, even shocks due to relatively low reactions against the engine torque are transmitted to the vehicle body, thus deteriorating the comfortability.

An object of the invention is to provide a rolling control apparatus for an engine, which can suppress the engine rolling by electronically varying the damping force according to the magnitude of the reaction against the engine torque.

According to the invention, there is provided a rolling control apparatus for an engine, which comprises a casing accommodating a liquid, a partitioning member secured to either the engine or the vehicle chassis and which divides the interior of the casing into two sections, mounting means for securing the walls of the two sections facing the partitioning member to either the engine or vehicle chassis to which the partitioning member is not secured, orifice means provided on the partitioning member, for controlling the communication between the two sections, accelerator throttle opening/closing velocity detecting means for checking whether the rate of change in the accelerator pedal angle is above a predetermined value, and control means for rendering the orifice means operative to restrict the communication between the two sections for a predetermined period of time in response to a signal from the accelerator throttle opening/closing velocity detecting means.

This invention can be more fully understood from the following detailed description when taken in conjunction with the accompanying drawings, in which: Fig. 1 is a plan view showing an engine room; Fig. 2 is an elevational view showing an engine and an engine mounting arrangement in the engine room of Fig. 1; Fig. 3 is a sectional view showing a shock absorber employed in a first embodiment of the invention; Fig. 4 is a plan view of the same shock absorber; Fig. 5A is a plan view of a rotary valve shown in Fig. 4; Fig. 5B is a sectional view taken along line VI--VI in Fig. 5A; Fig. 6 is a graph showing a spring characteristic, i.e., relation between the flexing of the rubber chamber wall members and the load of the shock absorber shown in Fig. 3;; Fig. 7 is a circuit diagram showing a control circuit of a second embodiment of the rolling control apparatus according to the invention; Fig. 8 is a circuit diagram showing a control circuit of a third embodiment of the rolling control apparatus according to the invention; Fig. 9 is a circuit diagram showing a control circuit of a fourth embodiment of the rolling control apparatus according to the invention; Fig. 10 is a schematic representation of a control circuit of a fifth embodiment of the rolling control apparatus according to the invention; Fig. 11 is a circuit diagram showing the detailed circuit construction of the individual blocks shown in Fig. 10; and Figs. 1 2A and 1 2B are waveform diagrams for explaining the operation of a chopper in the fifth embodiment.

A first embodiment of the invention will now be described with reference to Figs. 1 through 6. Fig. 1 is a plan view of an engine room, and Fig. 2 is an elevational view of an engine and an engine mounting arrangement in the engine room. In Figs. 1 and 2, engine 2 is shown mounted on a vehicle body or chassis 1. The engine 2 consists of an engine body 3 and an automatic transmission 5. The engine body 3 is supported by a first and second shock absorber 7 and 8, an engine mount 6 and a transmission mount 9. The first and second shock absorbers 7 and 8 are called front and rear rolling stoppers, respectively. They have the same construction, so only one of them will be described in detail with reference to Figs. 3 through 6. Fig. 3 is an elevational sectional view of a shock absorber 7 or 8.Referring to the figure, the shock absorber comprises a partitioning disc 41 which divides the interior of the shock absorber into two sections, i.e., upper and lower oil chambers 42 and 43. The partitioning disc 41 is secured to the vehicle chassis 1 (Fig. 1). Mounting screws 44 and 45 are mounted in the walls of the upper and lower oil chambers 42 and 43 facing the partitioning disc 41. They are secured to an arm member 10 extending from the engine body 3. The walls of the upper and lower oil chambers 42, 43, in which the stems of the mounting screws 44 and 45 are mounted, also define upper and lower flexing chambers 46 and 47, respectively. The upper oil chamber 42 is defined between the partitioning disc 41 and upper flexing chamber 46, and the lower oil chamber 43 is defined between the partitioning disc 41 and lower flexing chamber 47.The partitioning disc 41 has a diametrical bore 48 in which a rotary valve 50 is received. The bore 48 consists of a large diamter section 49 and a small diameter section 52. The rotary value 50 has a large diameter portion with a pointed end which is received in the large diameter section 49 of the bore 48. A small diameter portion 53 of the rotary valve 50 slideably penetrates the samll diameter section 52 of the bore 48. The large diameter portion 53 of the rotary valve 50 is formed with an elongated communication hole 54 having a large opening area and extending in the diametrical direction of the partitioning disc 41. The free end of the small diameter portion 53 of the rotary valve 50 is coupled to a solenoid 55.The rotary valve 50 can be rotated by 90" about its axis by the solenoid 55. The left end of the bore 48 is sealed by a cap 56 provided with an 0ring 57. The partitioning disc 41 has a large hole which is adapted to register with the communication hole 54 of the rotary valve 50. It also has a small hole 58. Orifice elbows 60 and 61, each having an orifice 59 of a constant sectional area and a constant length, are screwed in the upper and lower ends of the hole 58. The walls of the upper and lower flexing chambers 46 and 47 are provided on the side opposite the respective stopper plates 62 and 63. These walls have rubber protuberances 64. The rubber protuberances 64 on each flexing chamber wall consist of oppositeend rubber protuberances 64-1 having a relatively large height.Three intermediate rubber protuberances 64-2 having a relatively small height are provided at a uniform interval between the opposite-end rubber protuberances 64-1.

The rotary valve 50, solenoid 55, hole 58 and orifice elbows 60 and 61 constitute the orifice mechanism.

The operation of the first embodiment of the invention having the above embodiment will now be described. When the vehicle is running at a constant speed, the engine does not roll. Without any rolling, the communication hole 54 in the rotary valve 50 is vertical, that is, the upper and lowr oil chambers 42 and 43 communicate with each other via the conmunication hole 54 in synchronization with the hole in the partitioning disc 41 which has a relatively large area. In this situation, vibrations of the engine body 3 in the vertical direction, are lightly damped through the mounting screws 44 and 45, the upper and lower flexing chambers 46 and 47, and the upper and lower oil chambers 42 and 43 before being transmitted to the vehicle chassis 1.When the amplitude of the vertical vibration of the engine body 3 is gradually increased, the rubber protuberances 64-1 first strike and are then compressed by stopper plates 62 and 63. With a further increase of the engine body vibration amplitude, the rubber protuberances 64-2 are compressed. Fig.

6 shows the displacement of the upper and lower flexing chambers 46 and 47. The slope of the curve shown increases progressively. It will be seen that a great increase of the load on the upper and lower flexing chambers 46 and 47 can be absorbed with only a comparatively small amount of displacement.

When the accelerator pedal is being depressed at a rate in excess of a predetermined rate to increase the engine throttle valve aperture, the engine body 3 tends to roll due to the reaction against its torque. When the accelerator pedal depression rate exceeds a predetermined rate, the solenoid 55 is energized to cause the rotary valve 50 to rotate 90 . As a result, communication between the upper and lower oil chambers 42 and 43 by the rotary valve 50 is blocked. That is, the upper and lower oil chambers 42 and 43 can only communicate via the orifice 59. In this state, the rolling of the engine body 3 is greatly damped. When the amplitude of the rolling is large, the rubber protuberances 64 will help dampen the rolling.

The rolling of the engine body 3 is damped several seconds after it has been started.

Accordingly, the rotary valve 50 is rotated 90 to the initial position several seconds afterwards. The upper and lower oil chambers 42 and 43 can thus again communicate with each other via the communication hole 54 of the rotary valve 50. Now, vibrations of the engine body 3 are lightly damped by the shock absorbers 7 and 8 before being transmitted to the vehicle chassis 1.

With the shock absorbers as described above, in the absence of the rolling of the engine body 3, the vibrations thereof in the vertical direction are substantially absorbed by the elastic deformation of the engine mount 6, the transmission mount 9, the upper and lower flexing chambers 46 and 47, and the rubber protuberances 64 so that they are barely transmitted to the vehicle chassis 1. On the other hand, any rolling of the engine body 3 is heavily damped by the resistance offered to the fluid in the fluid path of the orifice 59, thus preventing the engine body 3 from striking other vehicle components in the engine room or the vehicle chassis. In addition, pitching of the vehicle body due to the rolling of the engine body 3 can be prevented.Further, since the displacement of the engine body 3 is minimized, the displacement piping extending from the engine body 3, such as the exhaust pipe, the cooling water duct, and the fuel duct, can also be minimized which is advantageous from the standpoint of effectively utlizing engine room space.

While in the above embodiment of orifice elbows 60 and 61 are provided, it is also possible to construct a rotary valve 50 which is also provided with an orifice corresponding to the orifice 59 so that it can block the communication between the upper and lower oil chambers 42 and 43 via the communication hole 54 while maintaining the communication with the orifice when engine body rolling causes the rotary valve 50 to rotate.

The provision of the orifice elbows 60 and 61 on the partitioning disc 41, however, facilitates the selection of the diameter and length of the orifice, and permits the desired orifice characteristics to be readily obtained while permitting machining expenditures to be reduced.

Further, the cap 56 may be dispensed with and instead, the left and of the rotary valve 50 in Fig. 3 may be sealed to the bore 48 with an O-ring. However, with the arrangement of the above embodiment, in which the bore 48 is sealed with the cap 56 and the rotary valve 50 has a conically pointed end facing the cap 56, the rotary valve 50 may be reduced in size and weight to facilitate its positioning and to ensure its light and smooth movement.

Fig. 7 shows a second embodiment of the rolling control apparatus according to the invention. Referring to the figure, reference numeral 71 designates an ignition coil, 72 a contact breaker, and 73 an ignition plug. As the contact breaker 72 is turned on or off, high voltage is applied to the ignition plug 73 to produce sparks in the engine cylinder. In this embodiment, the engine revolution is detected from a signal provided in accordance with the on-off operation of the contact breaker 72. More specifically, a signal appearing at the point of connection between the ignition coil 71 and the contact breaker 72 is fed to an engine revolution detecting circuit 74. The engine revolution detecting circuit 74 provides a voltage proportional to the engine revolution. It includes a shaper 75, a pulse width shaper 76, a low-pass filter 77 and a comparator 78.The shaper 75 shapes the input pulse voltage to have a pulse frequency equal to that of the engine revolution, the shaping including the removal of noise. The pulse width shaper 76 shapes the pulse width of the pulse-signal output of the shaper 75 to be constant. The pulse signal output of the pulse width shaper 76 is fed to the low-pass filter 77. The low-pass filter 77 provides a voltage proportional to the engine revolution to the comparator 78. The comparator provides an "H" level signal when the engine revolution is not higher than the reference value, e.g., 3,000 rpm.

Reference numeral 79 designates a vehicle speed senser which provides a vehicle speed pulse signal having a pulse frequency corresponding to the detected vehicle speed. The vehicle speed pulse signal from the vehicle speed sensor 79 is fed to a vehicle speed detecting circuit 80. The vehicle speed detecting circuit 80 includes a shaper 81, a frequency divider 82, a shaper 83, a timer 84 and a comparator 85. The shaper 81 shapes the waveform of the input vehicle speed pulse signal. The shaped vehicle pulse-signal output of the shaper 81 is fed to the frequency divider 82 for which divides the frequency by one-half. The output of the frequency divider 82 is fed to the shaper 83 for shaping its pulse width to be constant. The output of the shaper 83 is coupled through the timer 84 to the comparator 85 for comparing it to a reference.When the vehicle speed is 3 km/h or above, for instance, the comparator 85 provides an "H' '-level output signal. Reference numeral 86 designates a power source resetting circuit. When a power source is closed, the power source resetting circuit 86 feeds a reset signal to a clear terminal CL of a D-type flip4lop in the comparator 85.

Designated by 87 is an accelerator throttle opening sensor which detects the extent of the depression of the accelerator pedal. The output of the accelerator throttle opening sensor 87 is fed to an accelerator pedal depression rate detecting circuit 88. The accelerator pedal depression rate detecting circuit 88 provides an "H"-level signal when the rate of change in the accelerator throttle opening exceeds a predetermined value. For example, when the accelerator pedal is suddenly depressed, the accelerator pedal depression rate detecting circuit 88 provides an "H' '-level signal.

The output of the engine revolution detecting circuit 74, the vehicle speed detecting circuit 80 and the accelerator pedal depression rate detecting circuit 88 are fed to an AND gate 89. The output of the AND gate 89 is fed to one input terminal of the OR gate 90. Reference numeral 91 is a clutch switch which is closed when the clutch is coupled.

One end of the clutch switch 91 is connected, and a voltage of 8V is applied to its other end through a resistor R1. The point of connection between the resistor R1 and the clutch switch 91 is connected through an inverter 92 to the other input terminal of the OR gate 90. The output of the OR gate 90 is fed to a timer 93.

The timer 93 provides an "H"-level signal for a predetermined time from the instant of the reception of an "H"-level signal input. The output of the timer 93 is fed to a solenoid driving circuit 94. The solenoid driving circuit 94 feeds driving signals a and b to the respective shock absorbers 7 and 8 shown in Fig. 1 in response to an "H"-level signal input.

The operation of the second embodiment will now be described. When the engine revolution has a reference value, e.g., 300 rpm, or above, the output of the engine revolution detecting circuit 74 is at "L" level. Also, when the vehicle speed is lower than a reference speed, e.g., 3 km/h, the output of the vehicle speed detecting circuit 80 is at "L" level. Further, when the rate of the change of the accelerator throttle opening is less than a predetermined rate, the output of the accelerator pedal depression rate detecting circuit 88 is at "L" level. When at least one output from the engine revolution detecting circuit 74, the vechile speed detecting circuit 80, or the accelerator pedal depression rate detecting circuit 88 is at "L" level, the output of the AND gate 89 is also at "L" level so that the output of the timer 93 circuit is at "L" level.

Thus, the solenoid driving circuit 94 is not actuated and does not provided the driving signals a and b. In this situation, the upper and lower oil chambers 42 and 43 of each of the shock absorbers 7 and 8 communicate with each other via both the communication hole 54 and the orifice 59. The shock absorbers 7 and 3 thus provide light damping action against the back-and-forth movement of the engine body 3 to prevent the transmission of vibrations to the vehicle body 1.

When the engine revolution is lower than a reference value, e.g., 3,00 rpm, the output of the engine revolution detecting circuit 74 is at "H" level. Also, when the vehicle speed is at a reference speed, e.g., 3 km/h or above, the output of the vehicle speed detecting circuit 80 is at "H" level. Further, when the rate of change of the accelerator throttle opening is more than a predetermined rate the output of the accelerator pedal depression rate detecting circuit 88 is at "H" level. When the output of the engine revolution detecting circuit 74, the vehicle speed detecting circuit 80 and the accelerator pedal depression rate detecting circuit 88 are all at the "H" level, "H" output is provided from the AND gate 89. The timer circuit 93 thus provides "H" level output for a predetermined time.During this time, the solenoid driving circuit 94 is held active and provides the driving signals a and b. In response to the driving signals a and b, the rotary valve 50 of each of the shock absorbers 7 and 8 is rotated 90". Thus, the communication between the upper and lower oil chambers 42 and 43 via the communication hole 54 is blocked so that the two chambers can communicate with each other only via the sole orifice 59. The shock absorbers 7 and 8 thus provide greater damping force, i.e., heavier damping action on the back-and-forth movement of the engine body 3 for the predetermined time noted above.In other words, when the engine revolution is lower than the reference value (i.e., 3,000 rpm) and the vehicle speed is at the reference speed (i.e., 3 km/h) or above and the accelerator throttle opening is in excess of a predetermined value, the shock absorbers 7 and 8 effectively prevent the engine body 3 from forcefully rolling with respect to the vehicle body 1 due to the reaction against the engine torque.

When the automobile clutch is not coupled, the clutch switch 91 is "off". In this case, a voltage V1, i.e., an "H"-level signal, is supplied to the inverter 92 so that an "L' '-level signal is fed to the timer circuit 93. The output of the timer circuit 93 fed to the solenoid driving circuit 94 is at ''L'' level. The solenoid driving circuit 94 thus is not activated and does not provide the driving signals a and b. In this situation, i.e., with the clutch not coupled, the upper and lower oil chambers 42 and 43 communicate with each other via both the communication hole 54 and the orifice 59. The shock absorbers thus provide a light damping action against the movement of the engine body 3 and prevent the transmission of vibrations from the engine body 3 to the vehicle body 1.

When the clutch is coupled after changing gears, the clutch switch 91 is turned on so that a ground level (i.e., "L" level) signal is supplied to the inverter 92 so that an "H"level signal is fed to the timer circuit 93. The timer circuit 93 thus provides an "H"-level signal for a predetermined time, during which the solenoid driving circuit 94 is held active and provides the driving signals a and b.

Thus, communication between the upper and lower oil chambers 42 and 43 via the communication hole 54 is blocked so that the two chambers communicate with each other via the sole orifice 59. The shock absorbers thus provide a greater damping force, i.e., a heavier damping action on the back-and-forth movement of the engine body 3, for a predetermined time. In other words, subsequent to the coupling of the clutch after the gear change, the shock absorbers are rendered active to prevent the forceful rolling of the engine body 3 with respect to the vehicle body 1 due to the reaction against the engine torque.

As has been shown, with the second einbodiment a function of preventing the rolling of the engine body 3 with respect to the vehicle body 1 is provided for a predetermined period when a situation occurs in which the engine revolution is lower than a reference value (i.e., 3,000 rpm), the vehicle speed is at a reference speed ti.e., 3 km/h or above) and the rate of change in the accelerator throttle pedal has a predetermined value subsequent to the coupling of the clutch.

Now, a third embodiment of the rolling control apparatus according to the invention will be described with reference to Fig. 8.

Referring to the figure, reference numeral 71 designates an ignition coil, 72 a contact breaker, and 73 an ignition plug. As the contact breaker 72 is turned on and off, high voltage is applied to the ignition plug 73 to produce sparks in the engine cylinder. In this embodiment, the engine revolution is obtained from a signal provided in accordance with the on-off operation of the contact breaker 72. More specifically, a signal appearing at the point of connection between the ignition coil 71 and the contact breaker 72 is fed to an engine revolution detecting circuit 74. The engine revolution circuit 74 provides a voltage proportional to the engine revolution. It includes a shaper 75, a pulse width shaper 75 and a low-pass filter 77.The shaper 75 shapes the input pulse voltage to have a pulse frequency equal to the engine revolution, the shaping including removal of noise. -The pulse width shaper 76 shapes the pulse width of the pulse signal output of the shaper 75 to be constant. The voltage provided from the engine revolution detecting circuit 74 in proportion to the engine revolution, is fed to an engine rotational speed detecting circuit 100. The engine rotational speed detecting circuit 100 provides an "H"level signal when the change in the engine revolution exceeds a predetermined value. Its output signal is fed to a timer circuit 93. The timer circuit 93 provides an "H' '-level signal for a predetermined time from the instant it receives an "H"-level signal. Its output is fed to a solenoid driving circuit 94.The solenoid driving circuit 94 can feed driving signals a and b to the respective shock absorbers 7 and 8, as shown in Fig. 1, when it is rendered active by the "H"-level signal input.

The operation of a third embodiment having the above construction will now be described.

As noted before, the engine revolution detecting circuit 74 provides a voltage proportional to that of the engine revolution. The voltage signal provided from the engine revolution detecting circuit 74 in proportion to the engine revolution, is fed to the engine rotational speed detecting circuit 100, which detects a change in the engine revolution. When the change in the engine revolution is below a predetermined value, the output of the engine rotational speed detecting circuit 100 is at "L" level. The output of the timer circuit 93 is thus also at "L" level. Thus, the solenoid driving circuit 94 is not activated so and does not provide the driving signals a and b.

In this situation, the upper and lower oil chambers 42 and 43 of each of the shock absorbers 7 and 8 communicate with each other via both the communication hole 54 and the orifice 59. The shock absorbers thus provide a light damping action against the movement of the engine body 3 to prevent the transmission of vibrations from the engine body 3 to the vehicle chassis 1.

When the change in the engine revolution exceeds a predetermined value, the engine rotational speed detecting circuit 100 provides an "H"-level signal. The time circuit 93 thus provides an "H"-level output for a predetermined time. During this time, the solenoid driving circuit 94 is held active and provides the driving signals a and b. In response to the driving signals a and b, the rotary valve 50 of the shock absorbers 7 and 8 rotates 90 , thus blocking the communication between the upper and lower oil chambers 42 and 43 via the communication hole 54 so that the two chambers communicate with each other via the sole orifice 59. The shock absorbers thus provide greater damping force, i.e., heavier damping action, on the back-and-forth movement of the engine body 3 for a predetermined time.In other words, when the change in the engine revolution exceeds a predetermined value, the shock absorbers are rendered active and prevent the forceful rolling of the engine body 3 with respect to the vehicle body 1 due to the reaction against the engine torque.

As described above, a function of the third embodiment is to prevent the rolling of the engine body 3 with respect to the vehicle body 1 for a predetermined period of time when the change in the engine revolution exceeds a predetermined value.

A fourth embodiment of the rolling control apparatus according to the invention will now be described with reference to Fig. 9. Referring to the figure reference numeral 87 designates an accelerator throttle opening sensor which detects the extent of the depression of the accelerator pedal. The accelerator throttle opening sensor 87 has a tap A which is movable according to the extent of the depression of the accelerator pedal. When the accelerator pedal is depressed, tap A is moved in the direction of arrow B. Voltage appearing at the tap A is fed to an accelerator throttle opening/closing velocity detecting circuit 88.

The accelerator throttle opening/closing velocity detecting circuit 88 provides an "H"-level signal when the accelerator throttle opening velocity is, for instance, 0.5 m/sec. or above, or when the accelerator throttle closing velocity is, for instance 0.8 m/sec. or above. The voltage generated at tap A is fed to a plus input terminal of a differential amplifier 102 through an integrator consisting of a resistor R1 and a capacitor C1. A resistor R2 is connected between the output terminal of the operational amplifier 102 and the ground.

Designated at D1 and D2 are diodes. The voltage generated across the resistor R2 is fed to a minus input terminal of the differential amplifier 1 02. The output terminal of the differential amplifier 1 02 is connected through a capacitor C2 and a resistor R3 to point B connecting the resistors R5 and R6 in a voltage divider consisting of a series of resistors R4 to R7. Point C connecting the capacitor C2 and the resistor R3 is connected to a plus signal terminal of a first comparator 103 which compares the throttle opening velocity and also is connected to a minus input terminal of a second comparator 104 which compares the throttle closing velocity.

Point D connecting the resistors R6 and R7 is connected to a minus input terminal of the first comparator 103, and point E connecting the resistors R4 and R5 is connected to a plus input terminal of the second comparator 104.

The output terminals of the first and second comparators 103 and 104 are connected to the base of a transistor Q1, which grounds the emitter.

The collector output of the transistor Q1 is fed to a timer circuit 105. When it receives an "H"-level signal, the timer circuit 105 provides an "H' '-level signal for a period T1. The output of the timer circuit 105 is fed through an OR gate 106 to a solenoid driving circuit 107 consisting of power transistors Q1 and Q2. The collector of the transistor Q2 is connected to the solenoid 55, shown in Fig.

3, providing a heavy damping action for each of the shock absorbers 7 and 8.

The output of the timer circuit 105 is fed to another timer circuit 108. The timer circuit 108 provides an "H' '-level signal for a predetermined period T2 in response to the "H"level signal input. The output of the timer circuit 108 is fed to one input terminal of an AND gate 109, which receives at the other input terminal of a pulse signal from an oscillator (not shown). The pulse width of the pulse signal of the oscillator is set to be far smaller than the pulse width of the output of the timer circuits 105 and 108. The output of the AND gate 109 is fed to the OR gate 106.

The operation of a fourth embodiment having the above construction will now be described. When the accelerator pedal is quickly depressed, tap A of the accelerator throttle opening sensor 87 is moved in the direction of arrow B. Voltage fed to the plus input terminal of the differential amplifier 102 thus is increased according to the extent that the acclerator pedal is depressed. The voltage of the polarity shown is thus generated across the capacitor C2 according to the rate of the depression of the accelerator pedal. If the resistance of the resistors R4 to R7 is set such that the first comparator 103 provides an "L''-level signal when the accelerator pedal depression rate exceeds 0.5 m/sec., for instance, the output of the first comparator 103 goes to the "L" level when the accelerator pedal depression rate exceeds 0.5 m/sec.As a result, the output of the accelerator throttle opening/closing velocity detecting circuit 88 goes to "H" level. Thus, the timer circuit 105 provides an "H"-level output for a predetermined period T1, during which the solenoid driving circuit 107 is held active. With the solenoid driving circuit 107 rendered active, the solenoid 55 is energized to cause the solenoid valve 50 to rotate 90". Thus, communication between the upper and lower oil chambers 42 and 43 via the conmunication hole 54 is blocked so that the two chambers communicate with each other via the sole orifice 59. The shock absorbers 7 and 8 thus provide a greater damping force, i.e., heavier damping action on the back-and-forth movement of the engine body 3 for the predetermined period noted above.

With the change of the output level of the timer circuit 105 to the ''H" level, the timer 108 is started in synchronism thereto and provided an "H"-level signal for a period T2, during which time the pulse signal from the oscillator is fed through the AND gate 109 and the OR gate 106 to the solenoid driving circuit 107. Since the period T2 is set to be longer than the period T1, the timer circuit 108 will continue to provide an "H"-level signal subsequent to the lapse of the period T1. This causes the solenoid driving circuit 107 to switch on and off, thus eliminating shocks that may otherwise be caused to the solenoid at the time of the recovery of the light damping action. The generation of noise at this time thus can be prevented.

When the accelerator pedal is quickly returned, the tap A of the accelerator throttle opening sensor 87 is moved in the direction opposite to the direction of arrow B. Thus, voltage fed to the plus input terminal of the differential amplifier 102 is lowered according to the extent of the return of the accelerator pedal. The output voltage of the differnetial amplifeir 102 is thus reduced. Thus, a voltage of opposite polarity is generated across the capacitor C2 according to the accelerator pedal return rate. The voltage fed to the minus input terminal of the second comparator 104 is thus increased according to the rate of return of the accelerator pedal.If the resistances of the resistors R4 to R7 are set such that the second comparator 104 provides an "L"-level signal when the accelerator pedal return rate exceeds 0.8 m/sec., for example, the second comparator 104 provides an "L"level signal when this conditin is satisfied. As a result, the accelerator throttle opening/closing velocity detecting circuit 88 provides an "H"-level output, causing the timer circuit 105 to provide an "H"-level output for the predetermined period T1. Thus, the same action as when the acceledator pedal is quickly depressed as described before is brought about.

As has been shown, with the fourth embodiment a function of preventing the engine body 3 from rolling greatly with respect to the vehicle body 1 can be obtained when the accelerator pedal opening velocity exceeds A m/sec., or when the accelerator closing velocity exceeds B m/sec.

In addition, the difference between the reaction against the engine torque when the accelerator pedal is quickly depressed and that when the accelerator pedal is quickly returned, can be taken into considerations by setting A < B. The reaction is greater when the accelerator pedal is quickly depressed for the same change in the accelerator throttle aperture. The setting of the condition A < B permits a heavier damping action to be brought about more quickly when the accelerator pedal is depressed quickly.

A fifth embodiment of the rolling control apparatus according to the invention will now be desicrbed with reference to Figs. 10 through 12. Fig. 10 is a block diagram of this embodiment of the rolling control apparatus.

Fig. 11 shows the detailed circuit construction of the individual blocks shown in Fig. 10.

Referring to these figures, reference numeral 111 designates a potentiometer for detecting the accelerator throttle opening, i.e., the accelerator pedal depression angle. The potentiometer 111 generates a detection signal proportional to the throttle opening. The detection signal is fed to a throttle opening/closing velocity detecting circuit 112. The throttle opening/closing velocity detecting circuit 11 2 detects the throttle opening/closing velocity and provides an "H"-level signal when the throttle opening velocity or the throttle closing velocity exceeds a predetermined value.The detection signal proportional to the throttle opening provided from the potentiometer 111 is also fed to a throttle opening detecting circuit 11 3. The throttle opening detcting circuit 11 3 checks whether the throttle opening is less than a predetermined value, and its provides an "L"-level signal when this condition is satisifed. Reference nuermal 14 designates an engine revolution sensor for which detects engine revolution and produces an engine rotation signal. The engine rotation signal is fed to an engine revolution detecting circuit 11 5. The engine revolution detecting circuit 11 5 checks whether the engine revolution is less than a predetermined value, and it provides an "L"-level signal when this condition is satisifed.The output signals of the throttle opening detecting circuit 11 3 and the engine revolution detecting circuit 11 5 are fed to an OR gate 116. Reference numeral 117 designates a gear change detecting circuit, which receives gear change signals A and B supplied from an electronic automatic transmission (not shown) and checks for a gear change according to the signals A and B.

More specifically, the gear change detecting circuit 11 7 checks whether a gear change from first gear to fourth gear has been done.

When the gear change is made, it provides an "H"-level signal. The signals from the OR gate 116 and the gear change detecting circuit 117 are fed to an AND gate 118. Reference numeral 11 9R designates an "R" (reverse) position switch, which is turned on when a selector lever (not shown) is set to "R".Reference numeral 11 9D designates a "D" (drive) position switch, switch is turned on when the selector lever is set to "D" The outputs of the "R" and "D" position switches 119R and 11 9D are fed to an inhibitor switch on-off detecting circuit 11 9. The inihibitor switch on-off detecting circuit 11 9 provides an "H' '-level signal every time the "R" or "D" position switch 11 9R or ll9D is turned on or off. Reference numeral 1 20 designates an external control switch which is turned on when testing the shock absorbers.A signal which is provided from the control switch 1 20 when it is turned on, is fed to an input interface circuit 121, which provides signals which vary depending on the state of the switch 1 20. More specifically, when the control switch 1 20 is turned on, the input interface circuit 121 provides an "H"-level signal.

The output of the throttle opening/closing velocity detecting circuit 112, the AND gate 118, the inhibitor switch on/off detecting circuit 119 and the input interface circuit 121 are fed to an OR gate 110, the output of which is in turn fed to a timer circuit 93. The timer circuit 93 serves to drive a solenoid driving circuit 107 for a predetermined period of time in response to an "H"-level signal input. The output of the input interface circuit 121 is also fed to a chopper circuit 122. The chopper circuit 122 perform its function at the trailing edge of the time pulse from the time circuit 93. When the output of the input interface circuit 121 goes to an "H"-level, the chopping control of the chopper circuit 122 is terminated.The output terminal of the solenoid driving circuit 107 is connected to one end of the solenoid 55 for driving the rotary valve 50 in the shock absorbers 7 and 8. The other end of the solenoid 55 is connected to the positive terminal of a battery 123, the negative terminal of which is grounded. The output ofthe solenoid driving circuit 107 is fed to a high temperature detecting circuit 124. When the temperature of the solenoid 55 is elevated due to the generation of heat, the high temperature detecting circuit 124 detects a reduction in the solenoid current flowing in the solenoid driving circuit 107, and it provides an "L"-level signal when the solenoid current becomes lower than the predetermined level. When an "L"-level signal is provided from the high temperature detecting circuit 124, the timer circuit 93 is forcibly stopped.

The positive terminal of the battery 1 23 is connected through a key switch 1 25 to a stable power supplying circuit 1 26 and a low voltage detecting circuit 127. The output of the low voltage detecting circuit 127 is fed to the timer circuit 93. When the voltage of the stable power supplying circuit 126: becomes lower than the predetermined level, the start of the timer circuit 93 is inhibited.

Fig. 11 is a circuit diagram showing the individual blocks in Fig. 10 in detail.

The operation of the fifth embodiment having the above construction will now be described. The voltage provided from the potentiometer 111 is varied according to the operation of the accelerator pedal. The throttle opening/closing velocity detecting circuit 11 2 checks whpther the throttle opening and closing velocities detected by the potentiometer 11 2 are above the predetermined values.

When the throttle opening or closing velocity exceeds the predetermined value, the throttle opening/closing velocity detecting circuit 112 provides an "H"-level signal. As a result, the timer circuit 93 is rendered operative to drive the solenoid driving circuit 107 for a predetermined period of time, during which the solenoid 55 is energized. The shock absorbers 7 and 8 are thus rendered effective to provide a heavier damping action on the engine rolling.

As has been shown1 when the throttle opening or closing velocity exceeds a predetermined value, the shock absorbers provide a heavier damping action on the engine rolling.

Now, the control operation that takes place when a gear change is effected by the electronic automatic transmission, will be described. The gear change signals A and B provided from the electronic automatic transmission are fed to the gear change detecting circuit 117. The gear change detecting circuit 117 checks for a gear change from the first to the fourth gear from the gear change signals A and B. When the gear change from the first to the fourth gear is done, the gear change detecting circuit 11 7 provides an "H"-level signal.

When the throttle opening detecting circuit 11 3 detects that the throttle opening is above a predetermined value or when the engine revolution detecting circuit 11 5 detects that the engine revolution is above a predetermined value, the throttle opening detecting circuit 11 3 or the engine-revolution detecting circuit 11 5 provides an "H' '-level signal. As a result, a gear change is effected by the electronic automatic transmission. In addition, when the throttle opening exceeds a predetermined value or when the engine revolution exceeds a predetermined value, the AND gate 118 provides an "H"-level signal to the timer circuit 93.As a result, the solenoid driving circuit 107 is driven for a predetermined period of time, during which the solenoid 55 is energized. In response to the driving signals a and b, the rotary valve 50 of each of the shock absorbers 7 and 8 is rotated 90 to cut the communication between the upper and lower oil chambers 42 and 43 via the communiation hole 54, so that the two chambers communicate with each other via the sole orifice 59. The shock absorbers thus provide greater damping force, i.e., a heavier damping action, on the back-and-forth movement of the engine body 3 for a predetermined time. That is, forceful rolling of the engine body 3 with respect to the vehicle chassis 1 due to the reaction against the engine torque is prevented.

When the throttle opening and the engine revolution are below a predetermined value, the output of the OR gate 116 is at "L" level.

In this case, even if a gear change is effected by the electronic automatic transmission, the output of the AND gate 118 remains at "L" level, so that the timer circuit 93 is not rendered operative. In other words, even if a gear change is done by the electronic automatic transmission, the damping function is not switched to the heavier one so long as the engine revolution and throttle opening below a predetermined value.

Further, whenever the "R" or "D" position switch 11 9R or 11 9D is turned on or off, the inhibitor switch on/off detecting circuit 11 9 provides an "H"-level signal, which is fed to the timer circuit 93. Thus, the solenoid driving circuit 107 is driven for a predetermined period of time, during which the solenoid 55 is energized to provide for a heavier damping action on the engine body 3 to-prevent the rolling thereof with respect to the vehicle body 1.

When the shock abosrbers 7 and 8 are tested, the external control switch 120 is turned on. As a result, the output of the input interface circuit 121 goes to an "H"-level, which is fed to the timer circuit 93. Thus, the solenoid driving circuit 107 is driven for a predetermined period, during which the solenoid 55 is energized to render the shock absorbers 7 and 8 effective to provide a heavier damping action on the engine body.

When the external control switch 1 20 is turned on, the chopper circuit 1 22 is grounded through the input interface circuit 1 21 and the external control switch 120, as is obvious from Fig. 11. Consequently, the chopper circuit 122 no longer provides the chopping control that is otherwise provided at the falling of the timer pulse from the timer circuit 93. Thus, with the falling of the timer pulse of the timer circuit 93, the output of the solenoid driving circuit 107 stops. As a result, a shock sound is generated by the sudden striking of the shock absorbers due to return spring forces therein. Thus, the restoration of the shock absorbers to their inoperative position can be comfirmed in the testing. The detailed operation of the chopper circuit 122 will be described later in detail.

When the shock absorbers 7 and 8 are frequently driven, the solenoid 55 is heated, so that it is deteriorated or smoke is generated from it. This is prevented by detecting the current through the solenoid 55. More specifically, the detection is done by making use of the fact that the current through the solenoid 55 is reduced when the temperature thereof is increased. The current through the solenoid 55 is fed through the solenoid driving circuit 107 to the high temperature detecting circuit 1 24. The high temperature detecting circuit 1 24 can thus detect a reduction of the current through the solenoid 55. When the current through the solenoid becomes lower than a predetermined level, it forcibly stops the timer circuit 93, whereby the solenoid driving circuit 107 is forcibly stopped.In this way, it is possible to prevent the deterioration of the solenoid 55 or smoke generated therefrom due to heating thereof.

The operation of the chopper circuit 1 22 will now be described with reference to Figs.

11, 1 2A and 12B. The chopper circuit 122 provides a sawtooth wave output, as shown at a in Fig. 1 2A to a plus input terminal of a comparator 93-1 in the timer circuit 92 shown in Fig. 11. When the timer circuit 93 is stopped, the voltage fed to a minus input terminal of the comparator 93-1 is reduced as shown by a curve b. Consequently, there occur intermittent periods A, during which the sawtooth wave voltage a is lower than the voltage b at the minus input terminal. During the periods A, the comparator 93-1 provides an "L' '-level output. The solenoid driving circuit 107 is thus intermittently driven during the periods A, as shown in Fig. 1 2B. It is to be understood that with the provision of the chopper circuit 122, the solenoid driving circuit 107 is intermittently operated for a predetermined period of time subsequent to the stopping of the timer circuit 93. It is thus possible to prevent the generation of the shock sound due to the striking of the shock absorbers 7 and 8, which is caused by the internal spring force therein.

Claims (14)

1. A rolling control apparatus for an engine comprising: a casing accommodating a liquid; a partitioning member secured to either the engine or a vehicle chassis and dividing the interior of said casing into two sections; mounting means for securing the walls of said two sections, facing said partitioning member, to either the engine of the vehicle chassis to which the partitioning member is not secured; orifice means provided on said partitioning member for controlling the communication between said two sections; accelerator throttle opening/closing velocity-detecting means for checking whether the rate of change of the accelerator pedal angle is above a predetermined value; and control means for rendering said orifice means operative to restrict the communication between said two sections for a predetermined period of time in response to a signal from said accelerator throttle opening/closing velocity-detecting means.

2. A rolling control apparatus according to claim 1, wherein said orifice means includes: a valve mechanism for controlling the on-off communication between said two sections; and an orifice communicating said two sections with each other.

3. A rolling control apparatus according to claim 2, wherein said valve mechanism includes: a bore formed in said partitioning member; a rotary valve received in said bore; driving means for controlling the rotational position of said rotary valve; and a liquid-tight cap facing a pointed end of said rotary valve and sealing an open end of said bore.

4. A rolling control apparatus according to claim 1, wherein the outer surfaces of the walls of said two sections are provided with elastic protuberance capable of being engaged with the engine or vehicle chassis when the walls are displaced beyond a predetermined distance.

5. A rolling control apparatus according to claim 1, further comprising: engine-revolution detecting means for checking whether the revolution of the engine is lower than a predetermined value; and control means for rendering said orifice means operative for a constant period of time when signals are provided from said accelerator throttle opening/closing velocity-detecting means and engine-rotation detecting means.

6. A rolling control apparatus according to claim 5, further comprising: vehicle speed detecting means for checking whether the speed of the vehicle is above a predetermined value; and control means for rendering said orifice means operative for a constant period of time when signals are provided from said accelerator throttle opening/closing velocity-detecting means, engine-revolution detecting means and vehicle speed-detecting means.

7. A rolling control apparatus according to claim 5 or 6, further comprising: accelerator throttle opening/closing velocity-detecting means for checking whether the rate of change of the throttle valve opening is above a predetermined value.

8. A rolling control apparatus according to claim 5 or 6, further comprising: engine rotational speed-detecting means for checking whether the rotational speed of the engine is above a predetermined value.

9. A rolling control apparatus according to claim 5, further comprising: clutch-state detecting means for detecting the state of the clutch; and control means for rendering said orifice means operative for a predetermined period of time when signals are provided from said engine-revolution detecting means and accelerator throttle opening/closing velocity-detecting means are provided, or when a signal from said clutch-state detecting means is provided.

10. A rolling control apparatus according to claim 1, further comprising: accelerator throttle opening/closing velocity-detecting means for detecting the rate of change of the accelerator pedal angle; and control means for operating said orifice means to restrict the communication between said two sections for a predetermined period of time when the rate of change of the accelerator pedal angle in the depresing direction, provided from said accelerator throttle opening/closing velocity-detecting means, is above A m/sec. and when the rate of change of the accelerator pedal angle in the returning direction is above B m/sec.

11. A rolling control apparatus according to claim 3, wherein said driving means consists of a solenoid and that said apparatus furthr comprises: a timer circuit for operating said solenoid to restrict the communication between said two sections for a predetermined period of time in response to a signal from said accelerator throttle opening/closing velocity-detecting means; and a chopper circuit for effecting a chopping control to gradually reduce the solenoid current subsequent to the disappearance of the output of said timer circuit.

12. A rolling control apparatus according to claim 11, further comprising: diagnosis mode setting means for causing a pseudo-operation of said control means; and means for rendering said chopper circuit inoperative when the pseudo-operation of said diagnosis mode setting means is caused by said control means.

1 3. A rolling control apparatus according to claim 11, further comprising: temperature detecting means for detecting the temperature of said solenoid; and means for inhibiting the operation of said timer circuit when the temperature detected by said temperature detecting means exceeds a predetermined value.

14. A rolling control apparatus, substantially as hereinbefore described with reference to the accompanying drawings.