JPS6327598B2 - - Google Patents
Info
- Publication number
- JPS6327598B2 JPS6327598B2 JP8987579A JP8987579A JPS6327598B2 JP S6327598 B2 JPS6327598 B2 JP S6327598B2 JP 8987579 A JP8987579 A JP 8987579A JP 8987579 A JP8987579 A JP 8987579A JP S6327598 B2 JPS6327598 B2 JP S6327598B2
- Authority
- JP
- Japan
- Prior art keywords
- solenoid valve
- current
- circuit
- driving transistor
- signal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000010521 absorption reaction Methods 0.000 claims description 23
- 238000001514 detection method Methods 0.000 claims description 20
- 230000007423 decrease Effects 0.000 claims description 5
- 230000002238 attenuated effect Effects 0.000 claims description 3
- 230000010354 integration Effects 0.000 claims 1
- 238000010586 diagram Methods 0.000 description 10
- 238000002347 injection Methods 0.000 description 3
- 239000007924 injection Substances 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 230000004043 responsiveness Effects 0.000 description 3
- 229920006395 saturated elastomer Polymers 0.000 description 3
- 239000003990 capacitor Substances 0.000 description 2
- 230000004044 response Effects 0.000 description 2
- 230000000630 rising effect Effects 0.000 description 2
- 230000004913 activation Effects 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 230000001939 inductive effect Effects 0.000 description 1
Landscapes
- Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
- Magnetically Actuated Valves (AREA)
Description
【発明の詳細な説明】
本発明は、電磁弁、たとえば内燃機関の電子制
御燃料噴射装置における電磁式噴射弁などを小電
力で応答性良く駆動するための電流制御装置に関
するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a current control device for driving an electromagnetic valve, such as an electromagnetic injection valve in an electronically controlled fuel injection system for an internal combustion engine, with low electric power and with good responsiveness.
電磁式噴射弁（以下、電磁弁という）のような
低インピーダンスの誘導性負荷を直流電源で駆動
する場合、一般に行なわれているように、電流制
限素子として直列抵抗を用いた方式では、抵抗に
よる電力損失が大きく、かつ起動電流の立上がり
が抑制されて応答性も良くない。 When driving a low-impedance inductive load such as an electromagnetic injection valve (hereinafter referred to as a solenoid valve) with a DC power supply, the commonly used method of using a series resistor as a current limiting element does not Power loss is large, and the rise of the starting current is suppressed, resulting in poor responsiveness.
この欠点を改善するため、直列抵抗の代わりに
トランジスタのスイツチングによつて電磁弁の電
流を所望のごとく制御しようとする試みがなされ
ている。第１図はその原理説明図、第２図は第１
図各部の電圧電流波形図である。第１図におい
て、１は電磁弁、２は該電磁弁に直列接続された
駆動用トランジスタ、３は該トランジスタのエミ
ツタ側に接続された電流検出抵抗、４は該電磁弁
に並列接続されたフリーホイールダイオード５を
含む逆起電力吸収回路、（＋）は電源の正電位線
である。 In order to improve this drawback, attempts have been made to control the current of the solenoid valve as desired by switching transistors instead of series resistors. Figure 1 is a diagram explaining the principle, Figure 2 is the first diagram.
It is a voltage-current waveform diagram of each part of the figure. In Fig. 1, 1 is a solenoid valve, 2 is a drive transistor connected in series to the solenoid valve, 3 is a current detection resistor connected to the emitter side of the transistor, and 4 is a free circuit connected in parallel to the solenoid valve. A back electromotive force absorption circuit includes a wheel diode 5, and (+) is a positive potential line of the power supply.
上記回路において、トランジスタ２をオン、オ
フさせた場合、電磁弁１に流れる電流を考える
と、トランジスタ２が導通し電磁弁１に直流起電
力が印加されたときは、電磁弁１、トランジスタ
２、抵抗３を含むLR回路の時定数に従つて電流
が増加していく。次に、トランジスタ２が非導通
となり直流起電力が取り去られたときは、電磁弁
１に生じる逆起電力によりフリーホイールダイオ
ード５が導通して、逆起電力吸収回路４を通つて
電流が流れ、その電流は電磁弁１と逆起電力吸収
回路４の時定数に従つて減衰する。したがつて、
第２図のような制御信号を用いて、トランジス
タ２を通つて流れる電流が極大値IHHまで増加し
た時点t1でトランジスタ２を非導通とし、逆起電
力吸収回路４を通つて流れる電流が極小値IHLま
で減少した時点t2でトランジスタ２を導通させる
ようにすれば、電磁弁電流ILは第２図のような
波形となり、IHH、IHLの電流レベルの適当な設定
によつて起動後の電磁弁保持電流を所望のごとく
制御することができる。 In the above circuit, considering the current flowing through the solenoid valve 1 when the transistor 2 is turned on and off, when the transistor 2 conducts and a DC electromotive force is applied to the solenoid valve 1, the solenoid valve 1, the transistor 2, The current increases according to the time constant of the LR circuit including the resistor 3. Next, when the transistor 2 becomes non-conductive and the DC electromotive force is removed, the freewheel diode 5 becomes conductive due to the back electromotive force generated in the solenoid valve 1, and current flows through the back electromotive force absorption circuit 4. , the current attenuates according to the time constants of the solenoid valve 1 and the back electromotive force absorption circuit 4. Therefore,
Using a control signal as shown in FIG. 2, at time t1 when the current flowing through the transistor 2 increases to the maximum value IHH , the transistor 2 is made non-conductive, and the current flowing through the back electromotive force absorption circuit 4 is made non-conductive. If transistor 2 is made conductive at the time t2 when it has decreased to the minimum value IHL , the solenoid valve current IL will have a waveform as shown in Figure 2, and it can be changed by appropriately setting the current levels of IHH and IHL . Therefore, the holding current of the solenoid valve after startup can be controlled as desired.
この方式は、抵抗による電力消費が小さく、ま
た起動時の電流の立上がりが良いため開弁速度を
大きくできる利点を有しているが、問題は第２図
のような制御信号をどのようにして作るかにあ
る。 This method has the advantage of being able to increase the valve opening speed because the power consumption by the resistor is small and the current rises quickly at startup, but the problem is how to control the control signal as shown in Figure 2. It depends on how you make it.
第２図は逆起電力吸収回路４に流れる電流IF
の波形、はトランジスタ２および抵抗３に流れ
る電流IOの波形であり、IOにより抵抗３の出力端
に得られる電流検出信号ROIOの波形は、第２図
のように、と同一波形となる。この波形からわ
かるように、抵抗３をトランジスタ２のエミツタ
側に接続した場合には、トランジスタ２の非導通
期間に流れる電磁弁電流は抵抗３で検出できない
ため、第２図の信号をレベル比較器に入れても
電磁弁電流が極小値IHLとなる時点t2の検出ができ
ず、したがつて第２図のような制御信号を得る
ことは不可能である。 Figure 2 shows the current I F flowing through the back electromotive force absorption circuit 4.
is the waveform of the current I O flowing through the transistor 2 and the resistor 3, and the waveform of the current detection signal R O I O obtained from the I O at the output terminal of the resistor 3 is the same as shown in Figure 2. It becomes a waveform. As can be seen from this waveform, when resistor 3 is connected to the emitter side of transistor 2, the solenoid valve current flowing during the non-conducting period of transistor 2 cannot be detected by resistor 3. Even if the solenoid valve current reaches the minimum value IHL , the time t2 cannot be detected, and therefore it is impossible to obtain a control signal as shown in FIG.
これに対処するためには、電流検出抵抗３をト
ランジスタ２のコレクタ側に挿入して電磁弁電流
ILを検出する方法も考えられるが、このようにす
ると抵抗３がアース電位から浮いてしまうため、
前記したIHH、IHLの電流レベルの検出がむづかし
く、実現できたとしても非常に複雑な回路にな
る。 In order to deal with this, it is necessary to insert the current detection resistor 3 into the collector side of the transistor 2 to detect the solenoid valve current.
A method of detecting I L may also be considered, but this would cause resistor 3 to float away from the ground potential, so
Detection of the current levels of I HH and I HL described above is difficult, and even if it were possible, it would require a very complicated circuit.
本発明は上記の点にかんがみてなされたもの
で、その目的は電磁弁に流れる電流を駆動用トラ
ンジスタのスイツチングにより制御する場合、駆
動用トランジスタのエミツタ側に接続された電流
検出抵抗を用いて極めて簡単な回路で電磁弁電流
を所望のごとく制御できる装置を提供することに
ある。 The present invention has been made in view of the above points, and its purpose is to control the current flowing through a solenoid valve by switching a driving transistor, by using a current detection resistor connected to the emitter side of the driving transistor. An object of the present invention is to provide a device that can control a solenoid valve current as desired with a simple circuit.
上記目的を達成するため本願の第１の発明は、
駆動用トランジスタのエミツタ側から取り出され
た電流検出信号（第２図）を積分回路に入れ、
電磁弁電流波形（第２図）に対応して変化する
第２図に示すような積分波形としてレベル比較
器に入れることにより、電磁弁保持電流が極大、
極小となる時点t1、t2の検出が容易にできるよう
にしたものである。 In order to achieve the above object, the first invention of the present application is as follows:
The current detection signal (Fig. 2) taken out from the emitter side of the driving transistor is input into an integrating circuit,
By inputting the integrated waveform shown in Figure 2, which changes in response to the solenoid valve current waveform (Figure 2), into a level comparator, the solenoid valve holding current is maximized.
This makes it easy to detect the time points t 1 and t 2 when the value becomes minimum.
また、本願の第２の発明は、上記第１の発明に
おいて電磁弁に並列接続される逆起電力吸収回路
に制御用トランジスタを挿入し、該トランジスタ
により逆起電力吸収回路に流れる電流を制御し
て、前記積分回路の時定数による電流レベル検出
の時間遅れのために電磁弁起動電流の減衰時に電
流が過小となるのを防止するようにしたものであ
る。 Further, a second invention of the present application is such that, in the first invention, a control transistor is inserted into the back electromotive force absorption circuit connected in parallel to the solenoid valve, and the current flowing through the back electromotive force absorption circuit is controlled by the transistor. This prevents the current from becoming too small when the electromagnetic valve starting current is attenuated due to a time delay in detecting the current level due to the time constant of the integrating circuit.
以下、本発明の実施例を図面を用いて説明す
る。第３図は実施例の概念図、第４図は第３図中
の〜各部の信号波形図である。 Embodiments of the present invention will be described below with reference to the drawings. FIG. 3 is a conceptual diagram of the embodiment, and FIG. 4 is a signal waveform diagram of various parts in FIG.
第３図において、１１は電磁弁、１２は該電磁
弁に直列接続された駆動用トランジスタ１３と該
駆動用トランジスタのコレクタ、ベース間に接続
された定電圧ダイオード１４とバイアス抵抗１５
とで構成される電磁弁駆動回路、１６は駆動用ト
ランジスタ１３のエミツタ側に接続された電流検
出抵抗、１７は電磁弁１１に並列接続されたフリ
ーホイールダイオード１８およびこれと直列の制
御用トランジスタ１９を含む逆起電力吸収回路で
ある。 In FIG. 3, 11 is a solenoid valve, 12 is a driving transistor 13 connected in series with the solenoid valve, and a constant voltage diode 14 and a bias resistor 15 connected between the collector and base of the driving transistor.
16 is a current detection resistor connected to the emitter side of the driving transistor 13; 17 is a freewheel diode 18 connected in parallel to the solenoid valve 11; and a control transistor 19 connected in series with the solenoid valve drive circuit. This is a back electromotive force absorption circuit including:
２０は電流検出抵抗１６の出力信号を被比較
入力とし、電磁弁起動電流の最大値IMAXに相当す
る比較レベルをもつ第１比較器で、この第１比較
器は、被比較入力がIMAX相当レベルまで増加した
とき、出力がHIGHからLOWに反転し、その後
被比較入力がゼロになるまで出力がLOWに保持
されるヒステリシス特性を有している。２１は電
流検出抵抗１６の出力信号が入力される積分回
路、２２は該積分回路の出力信号を被比較入力
とし、電磁弁保持電流の極大値IHHおよび極小値
IHLに相当する比較レベルをもつ第２比較器で、
この第２比較器は、被比較入力がIHH相当レベル
まで増加したとき、出力がHIGHからLOWに反
転し、次に被比較入力がIHL相当レベルまで減少
したとき、出力がLOWからHIGHにもどるヒス
テリシス特性を有している。第１比較器２０の出
力と第２比較器２２の出力はNOR回路２３
で論理演算され、その出力をとする。 Reference numeral 20 denotes a first comparator which takes the output signal of the current detection resistor 16 as the compared input and has a comparison level corresponding to the maximum value I MAX of the solenoid valve starting current. It has a hysteresis characteristic in which the output inverts from HIGH to LOW when it increases to a corresponding level, and then remains LOW until the compared input becomes zero. 21 is an integrating circuit into which the output signal of the current detection resistor 16 is input; 22 is the output signal of the integrating circuit as the input to be compared; the maximum value IHH and the minimum value of the solenoid valve holding current;
A second comparator with a comparison level corresponding to I HL ,
This second comparator switches its output from HIGH to LOW when the compared input increases to a level equivalent to I HH , and then changes from LOW to HIGH when the compared input decreases to a level equivalent to I HL . It has a hysteresis characteristic that allows it to return. The output of the first comparator 20 and the output of the second comparator 22 are connected to a NOR circuit 23.
A logical operation is performed on , and the output is .
一方、インバータ２４の入力には電磁弁１１
の開弁時間幅を定める制御信号が与えられ、イン
バータ２４の出力と前記NOR回路出力とは
NOR回路２５で論理演算され、その出力は駆
動用トランジスタ１３のベースに入力される。 On the other hand, the solenoid valve 11 is connected to the input of the inverter 24.
A control signal that determines the valve opening time width is given, and the output of the inverter 24 and the output of the NOR circuit are
A logical operation is performed by the NOR circuit 25, and its output is input to the base of the driving transistor 13.
２６は逆起電力吸収制御回路で、この逆起電力
吸収制御回路は第２比較器２２の出力と電磁弁
１１の開弁時間幅を定める制御信号を入力し、そ
の出力で制御用トランジスタ１９のベース電流
を制御する。 Reference numeral 26 denotes a back electromotive force absorption control circuit, which inputs the output of the second comparator 22 and a control signal that determines the opening time width of the solenoid valve 11, and uses the output to control the control transistor 19. Control base current.
次に、第４図を用いて動作を説明する。いま、
入力がHIGHになるとインバータ出力は
LOWとなり、このとき第１比較器出力と第２
比較器出力はHIGH、NOR回路出力はLOW
になつているので、NOR回路出力はLOWから
HIGHに変わる。このため、駆動用トランジスタ
１３は導通状態（飽和状態）となり、電磁弁１１
に起動電流が流れ始める。起動電流が増加し、こ
れに対応する電流検出抵抗１６の出力がIMAX相
当レベルに達すると第１比較器出力が反転して
LOWとなり、この出力状態は入力がHIGHに
ある間保持される。一方、第２比較器出力は起
動電流がIHHのレベルをこえたときからLOWに反
転しているので、起動電流がIMAXに達した時点で
NOR回路出力はHIGHに、NOR回路出力は
LOWに変わる。このとき、制御用トランジスタ
１９が非導通状態にあるものとすれば、駆動用ト
ランジスタ１３を通る電流のしや断により電磁弁
１１に誘起する逆起電力によつて定電圧ダイオー
ド１４が導通し、その電流の一部が駆動用トラン
ジスタ１３のベースに流入するため、駆動用トラ
ンジスタ１３は能動領域におかれ、その内部抵抗
によつて該駆動用トランジスタを通る電流は急速
に減衰し、電流検出抵抗１６の出力も電流に比
例して減少する。これに対応して積分回路出力
がIHL相当レベルまで下がると、第２比較器出力
がHIGHにもどるため、NOR回路出力は
LOWに、NOR回路出力はHIGHとなり、駆動
用トランジスタ１３は再び導通状態（飽和状態）
に移行する。そうすると、駆動用トランジスタ１
３に流れる電流は再び増加するが、電流検出信号
の増加に対応して積分回路出力がIHH相当レ
ベルまで増加すると、第２比較器出力のHIGH
からLOWへの反転によりNOR回路出力は
HIGHに、NOR回路出力はLOWに変わる。こ
のとき、逆起電力吸収制御回路２６の出力が
LOWになるようにしておくと、制御用トランジ
スタ１９が導通状態（飽和状態）となり、電磁弁
１１の逆起電力による電流が逆起電力吸収回路１
７に流れる。このときは定電圧ダイオード１４が
非導通で、駆動用トランジスタ１３はしや断状態
となつている。したがつて、電流検出信号もほ
ぼゼロとなるが、第２比較器２２の被比較入力
は積分回路２１の時定数により電磁弁電流の波
形に対応して変化するから、時定数の適当な選定
により電磁弁電流が極小値IHLに達した時点で被
比較入力もIHL相当レベルとなり、第２比較器
出力がHIGHにもどる。これによつてNOR回
路出力はLOWに、NOR回路出力はHIGHに
変わり、駆動用トランジスタ１３は再び導通状態
となる。以下同様に入力がLOWになるまで駆
動用トランジスタ１３はオン、オフを繰り返し、
電磁弁１１にはIHHとIHLの間で変化する保持電流
が流れる。第４図でT1は電磁弁起動期間、T2は
電磁弁保持期間を示し、保持期間中電磁弁は開弁
状態にある。 Next, the operation will be explained using FIG. now,
When the input becomes HIGH, the inverter output becomes
becomes LOW, and at this time, the first comparator output and the second
Comparator output is HIGH, NOR circuit output is LOW
, so the NOR circuit output changes from LOW to
Changes to HIGH. Therefore, the drive transistor 13 becomes conductive (saturated), and the solenoid valve 11
The starting current begins to flow. When the starting current increases and the corresponding output of the current detection resistor 16 reaches a level equivalent to I MAX , the first comparator output is inverted.
goes LOW and this output state is held while the input is HIGH. On the other hand, the second comparator output has been inverted to LOW since the starting current exceeded the I HH level, so when the starting current reaches I MAX ,
NOR circuit output is HIGH, NOR circuit output is
Changes to LOW. At this time, assuming that the control transistor 19 is in a non-conductive state, the constant voltage diode 14 becomes conductive due to the back electromotive force induced in the solenoid valve 11 due to the interruption of the current passing through the drive transistor 13. A portion of the current flows into the base of the driving transistor 13, thus placing the driving transistor 13 in the active region, and due to its internal resistance, the current passing through the driving transistor is rapidly attenuated, and the current sensing resistor The output of 16 also decreases in proportion to the current. Correspondingly, when the integrator circuit output falls to a level equivalent to IHL , the second comparator output returns to HIGH, so the NOR circuit output becomes
LOW, the NOR circuit output becomes HIGH, and the driving transistor 13 becomes conductive (saturated) again.
to move to. Then, driving transistor 1
The current flowing through the second comparator increases again, but when the integrator circuit output increases to a level equivalent to IHH in response to the increase in the current detection signal, the second comparator output becomes HIGH.
By inverting from to LOW, the NOR circuit output becomes
HIGH, the NOR circuit output changes to LOW. At this time, the output of the back electromotive force absorption control circuit 26 is
If it is set to LOW, the control transistor 19 becomes conductive (saturated), and the current due to the back electromotive force of the solenoid valve 11 flows into the back electromotive force absorption circuit 1.
It flows to 7. At this time, the constant voltage diode 14 is non-conducting, and the driving transistor 13 is in a cut-off state. Therefore, the current detection signal also becomes almost zero, but since the compared input of the second comparator 22 changes according to the waveform of the solenoid valve current due to the time constant of the integrating circuit 21, it is necessary to select an appropriate time constant. As a result, when the solenoid valve current reaches the minimum value IHL , the compared input also reaches a level equivalent to IHL , and the second comparator output returns to HIGH. As a result, the NOR circuit output changes to LOW, the NOR circuit output changes to HIGH, and the driving transistor 13 becomes conductive again. Similarly, the driving transistor 13 repeats on and off until the input becomes LOW.
A holding current that changes between I HH and I HL flows through the solenoid valve 11 . In FIG. 4, T 1 indicates the solenoid valve starting period, and T 2 indicates the solenoid valve holding period, during which the solenoid valve is in an open state.
上記のように、駆動用トランジスタのエミツタ
側から取り出された電流検出信号を適当な時定数
をもつ積分回路に入れ、その出力により電流レベ
ルの検出を行なつて、電磁弁保持期間に積分回路
出力が電磁弁保持電流の極小値相当レベルまで減
少したとき駆動用トランジスタを導通させ、積分
回路出力が電磁弁保持電流の極大値相当レベルま
で増加したとき駆動用トランジスタを非導通とす
るように制御すれば、極めて小さい電力損失で電
磁弁保持電流を所望のごとく制御できることは明
らかである。 As mentioned above, the current detection signal taken out from the emitter side of the driving transistor is input into an integrating circuit with an appropriate time constant, the current level is detected from the output, and the integrating circuit outputs the signal during the holding period of the solenoid valve. Control is performed so that when the output of the integrating circuit increases to a level corresponding to the maximum value of the solenoid valve holding current, the driving transistor is made conductive when the voltage decreases to a level corresponding to the minimum value of the solenoid valve holding current, and the driving transistor is made non-conductive when the output of the integrating circuit increases to a level corresponding to the maximum value of the solenoid valve holding current. For example, it is clear that the solenoid valve holding current can be controlled as desired with extremely small power loss.
ところで、上記説明では第４図のΔtの期間に
電磁弁電流をIMAXからIHLまで急速に減衰させるた
め、逆起電力吸収回路の制御用トランジスタ１９
を非導通状態としていたが、この場合、積分回路
２１の時定数により積分回路出力側の電圧変化
が入力側の電圧変化より遅れるため、点の電
位がIHL相当レベルに達しても点の電位は未だ
IHL相当レベルに達せず、点の電位がIHL相当レ
ベルまで下がり、第２比較器２２が反転出力を発
生する時点（波形におけるα）では、点の電
位はIHL相当レベルより低いIMIN相当レベルまで下
がる。Δtの期間制御用トランジスタ１９が非導
通であれば、電磁弁電流は駆動用トランジスタ
１３に流れる電流と等しいので、この場合電磁弁
電流もIMINレベルまで下がつてしまう。特に、
積分回路２１の時定数を大きくとつた場合には
IMINが極端に低くなるため、一旦全開位置に移動
した電磁弁のプランジヤが閉じかかり、開弁状態
が不安定となる恐れがある。 By the way, in the above explanation, in order to rapidly attenuate the solenoid valve current from I MAX to I HL during the period Δt in FIG. 4, the control transistor 19 of the back electromotive force absorption circuit
was in a non-conducting state, but in this case, due to the time constant of the integrating circuit 21, the voltage change on the output side of the integrating circuit lags behind the voltage change on the input side, so even if the potential at the point reaches a level equivalent to I HL , the potential at the point remains Not yet
At the time point (α in the waveform) when the potential at the point does not reach the level equivalent to I HL and the potential at the point falls to the level equivalent to I HL and the second comparator 22 generates an inverted output (α in the waveform), the potential at the point is I MIN which is lower than the level equivalent to I HL . drop to a considerable level. If the control transistor 19 is non-conductive for the period of Δt, the solenoid valve current is equal to the current flowing through the drive transistor 13, so in this case the solenoid valve current also drops to the I MIN level. especially,
When the time constant of the integrating circuit 21 is set large,
Since I MIN becomes extremely low, the plunger of the solenoid valve that has moved to the fully open position may begin to close, making the valve open state unstable.
第３図に示した逆起電力吸収制御回路２６は上
記の欠点をなくすために設けられたものであつ
て、この逆起電力吸収制御回路２６は、第４図
波形で示されるように、第２比較器出力の最初
の立上がり時点α以降の電磁弁保持期間には制御
用トランジスタ１９を飽和領域で動作させるが、
それ以前のΔtの期間には制御用トランジスタ１
９を能動領域で動作させ、Δtの期間に逆起電力
吸収回路１７に流す電流を制御用トランジスタ１
９の内部抵抗により適度に制御して第４図波形
のΔt期間における電流減衰曲線の傾斜を変化さ
せることにより、Δt期間の終り（波形のβ点）
における電磁弁電流がIHLレベルより低くならな
いようにしている。 The back electromotive force absorption control circuit 26 shown in FIG. 3 is provided to eliminate the above-mentioned drawbacks. The control transistor 19 is operated in the saturation region during the solenoid valve holding period after the first rising point α of the output of the two comparators.
In the period of Δt before that, the control transistor 1
9 is operated in the active region, and the current flowing through the back electromotive force absorption circuit 17 during the period Δt is controlled by the control transistor 1.
By changing the slope of the current decay curve during the Δt period of the waveform in Fig. 4 by appropriately controlling the internal resistance of 9, the end of the Δt period (β point of the waveform)
The solenoid valve current at the IHL level is prevented from falling below the IHL level.
第５図に本発明による回路構成の具体例を示
す。図中、第３図と同等の部分には同一符号を付
して示し、２７は定電圧ダイオード２８と分圧抵
抗２９，３０，３１で構成される基準電圧発生部
である。第１比較器２０と第２比較器２２は、演
算増幅器３２，３３の入力端子に与えられた被
比較入力が入力端子に与えられる基準電圧によ
つて設定された比較レベルをこえると、出力電圧
がHIGHからLOWに反転し、その出力電圧が抵
抗３４，３５を通して入力端子に帰還されるこ
とによつて比較レベルが下がり、被比較入力が反
転後の比較レベル以下になるまで出力電圧を
LOWに保持する公知のヒステリシス特性を有す
るレベル比較器であり、第１比較器２０には電流
検出抵抗１６の出力信号が被比較入力として与
えられ、第２比較器２２には電流検出抵抗１６の
出力信号をコンデンサ３６、抵抗３７からなる
積分回路２１で積分した信号が被比較入力とし
て与えられる。逆起電力吸収制御回路２６は、サ
イリスタ３８、トランジスタ３９およびサイリス
タ３８に並列接続された抵抗４０を備え、サイリ
スタ３８とトランジスタ３９は逆起電力吸収回路
１７の制御用トランジスタ１９のベース回路に直
列に接続されている。サイリスタ３８のゲートに
は第２比較器２２の出力信号がコンデンサ４
１、抵抗４２からなる微分回路を通して与えら
れ、トランジスタ３９のベースには第４図波形
で示される制御信号が与えられる。制御用トラン
ジスタ１９のベースと電源の正電位線との間には
バイアス用ダイオード４３が接続されている。 FIG. 5 shows a specific example of the circuit configuration according to the present invention. In the figure, the same parts as those in FIG. The first comparator 20 and the second comparator 22 output voltage when the compared inputs applied to the input terminals of the operational amplifiers 32 and 33 exceed the comparison level set by the reference voltage applied to the input terminals. is inverted from HIGH to LOW, and the output voltage is fed back to the input terminal through resistors 34 and 35, thereby lowering the comparison level, and the output voltage is maintained until the compared input becomes equal to or less than the comparison level after inversion.
This is a level comparator having a known hysteresis characteristic that holds the current at LOW. A signal obtained by integrating the output signal by an integrating circuit 21 consisting of a capacitor 36 and a resistor 37 is provided as an input to be compared. The back electromotive force absorption control circuit 26 includes a thyristor 38, a transistor 39, and a resistor 40 connected in parallel to the thyristor 38, and the thyristor 38 and the transistor 39 are connected in series to the base circuit of the control transistor 19 of the back electromotive force absorption circuit 17. It is connected. The output signal of the second comparator 22 is connected to the capacitor 4 at the gate of the thyristor 38.
1. A control signal shown in the waveform of FIG. 4 is applied to the base of the transistor 39. A bias diode 43 is connected between the base of the control transistor 19 and the positive potential line of the power supply.
トランジスタ３９は入力がHIGHになると導
通するが、電磁弁起動期間にはサイリスタ３８が
非導通状態にあるため、制御用トランジスタ１９
のベースには抵抗４０を通して浅い負バイアスが
与えられる。そのバイアスは、電磁弁起動電流が
減衰する第４図Δtの期間に制御用トランジスタ
１９を能動領域で動作させ、Δt期間の終りにも
電磁弁１１を開弁状態に十分維持できるだけの電
流を逆起電力吸収回路１７に流しうるように調整
されている。サイリスタ３８は、第４図波形の
最初の立上がり時点αにおいて微分回路４１，４
２に発生するパルス信号によつて導通する。サイ
リスタ３８が導通すると、抵抗４０は短絡され、
電磁弁保持期間中制御用トランジスタ１９を導通
状態とするに十分な深いバイアスが制御用トラン
ジスタ１９のベースに与えられる。 The transistor 39 becomes conductive when the input becomes HIGH, but since the thyristor 38 is in a non-conductive state during the solenoid valve activation period, the control transistor 19
A shallow negative bias is applied to the base of the resistor 40 through a resistor 40. The bias is such that the control transistor 19 is operated in the active region during the period Δt in FIG. It is adjusted so that it can flow into the electromotive force absorption circuit 17. The thyristor 38 connects the differentiating circuits 41 and 4 at the first rising time α of the waveform in FIG.
It becomes conductive due to the pulse signal generated at 2. When thyristor 38 conducts, resistor 40 is shorted;
A sufficiently deep bias is applied to the base of control transistor 19 to render control transistor 19 conductive during the holding period of the solenoid valve.
これ以外の各部の構成および動作は改めて説明
するまでもなく、第３図および第４図の説明から
容易に理解されよう。 The configuration and operation of each part other than this need not be explained again and can be easily understood from the explanation of FIGS. 3 and 4.
以上説明したように本発明によれば、積分回路
とレベル比較器からなる極めて簡単な回路を用い
て電磁弁保持期間に駆動用トランジスタをスイツ
チング動作させるに必要な電流レベルの検出がで
き、低損失で、かつ応答性の良い電磁弁の電流制
御装置を容易に構成することができる。さらに、
逆起電力吸収制御回路を設けて電磁弁起動電流の
減衰期間に電磁弁に流れる電流を制御することに
より、前記積分回路の時定数による電流レベル検
出の時間遅れのために開弁状態が不安定になるこ
とを防いで電磁弁を適確に動作させることができ
る。 As explained above, according to the present invention, it is possible to detect the current level required to switch the drive transistor during the holding period of the solenoid valve using an extremely simple circuit consisting of an integrating circuit and a level comparator, thereby achieving low loss. Therefore, a current control device for a solenoid valve with good responsiveness can be easily constructed. moreover,
By providing a back electromotive force absorption control circuit to control the current flowing through the solenoid valve during the decay period of the solenoid valve starting current, the valve opening state becomes unstable due to the time delay in detecting the current level due to the time constant of the integrating circuit. This allows the solenoid valve to operate properly by preventing this from occurring.
第１図は駆動用トランジスタのスイツチングに
よる電磁弁電流制御装置の原理説明図、第２図は
第１図各部の電圧電流波形図、第３図は本発明の
実施例の概念図、第４図は第３図各部の信号波形
図、第５図は本発明による回路構成の具体例を示
す図である。
１１……電磁弁、１３……駆動用トランジス
タ、１６……電流検出抵抗、１７……逆起電力吸
収回路、１８……フリーホイールダイオード、１
９……制御用トランジスタ、２０……第１比較
器、２１……積分回路、２２……第２比較器、２
３，２４，２５……論理演算回路、２６……逆起
電力吸収制御回路。
Fig. 1 is an explanatory diagram of the principle of a solenoid valve current control device using switching of a driving transistor, Fig. 2 is a voltage and current waveform diagram of each part of Fig. 1, Fig. 3 is a conceptual diagram of an embodiment of the present invention, Fig. 4 3 is a signal waveform diagram of each part, and FIG. 5 is a diagram showing a specific example of a circuit configuration according to the present invention. 11...Solenoid valve, 13...Drive transistor, 16...Current detection resistor, 17...Back electromotive force absorption circuit, 18...Freewheel diode, 1
9... Control transistor, 20... First comparator, 21... Integrating circuit, 22... Second comparator, 2
3, 24, 25...logic operation circuit, 26...back electromotive force absorption control circuit.
Claims (1)
トランジスタと、該駆動用トランジスタのエミツ
タ側に接続された電流検出抵抗と、前記電磁弁に
並列接続された逆起電力吸収回路と、前記電流検
出抵抗の出力信号を被比較入力とし電磁弁起動電
流の最大値に相当する比較レベルをもつ第１比較
器と、前記電流検出抵抗の出力端に接続された積
分回路と、該積分回路の出力信号を被比較入力と
し電磁弁保持電流の極大値および極小値に相当す
る比較レベルをもつ第２比較器と、電磁弁開弁時
間幅を定める制御信号と前記両比較器の出力信号
に基いて電磁弁起動期間に電磁弁起動電流が最大
値に達するまで前記駆動用トランジスタを連続し
て導通させる信号と、電磁弁起動電流の減衰後の
電磁弁保持期間に電磁弁保持電流が極小値まで減
少したとき前記駆動用トランジスタを導通させ、
電磁弁保持電流が極大値まで増加したとき前記駆
動用トランジスタを非導通とする信号を発生する
論理演算回路を具備したことを特徴とする電磁弁
の電流制御装置。 ２ 電磁弁と、該電磁弁に直列接続された駆動用
トランジスタと、該駆動用トランジスタのエミツ
タ側に接続された電流検出抵抗と、前記電磁弁に
並列接続されたフリーホイールダイオードおよび
これと直列の制御用トランジスタを含む逆起電力
吸収回路と、前記電流検出抵抗の出力信号を被比
較入力とし電磁弁起動電流の最大値に相当する比
較レベルをもつ第１比較器と、前記電流検出抵抗
の出力端に接続された積分回路と、該積分回路の
出力信号を被比較入力とし電磁弁保持電流の極大
値および極小値に相当する比較レベルをもつ第２
比較器と、電磁弁開弁時間幅を定める制御信号と
前記両比較器の出力に基いて電磁弁起動期間に電
磁弁起動電流が最大値に達するまで前記駆動用ト
ランジスタを連続して導通させる信号と、電磁弁
起動電流の減衰後の電磁弁保持期間に電磁弁保持
電流が極小値まで減少したとき前記駆動用トラン
ジスタを導通させ、電磁弁保持電流が極大値まで
増加したとき前記駆動用トランジスタを非導通と
する信号を発生する論理演算回路と、前記第２比
較器の出力信号と、電磁弁開弁時間巾を定める制
御信号により前記制御用トランジスタを電磁弁起
動電流の減衰時には能動領域で動作させ、電磁弁
保持期間には飽和領域で動作させる逆起電力吸収
制御回路を具備したことを特徴とする電磁弁の電
流制御装置。[Claims] 1. A solenoid valve, a driving transistor connected in series to the solenoid valve, a current detection resistor connected to the emitter side of the driving transistor, and a back emitter connected in parallel to the solenoid valve. a power absorption circuit; a first comparator that uses the output signal of the current detection resistor as a comparison input and has a comparison level corresponding to the maximum value of the electromagnetic valve starting current; and an integration circuit connected to the output terminal of the current detection resistor. a second comparator which uses the output signal of the integrating circuit as a comparison input and has a comparison level corresponding to the maximum value and minimum value of the solenoid valve holding current, and a control signal that determines the solenoid valve opening time width and the comparison between the two. A signal that continuously conducts the driving transistor until the solenoid valve starting current reaches the maximum value during the solenoid valve starting period based on the output signal of the solenoid valve, and a signal that makes the driving transistor conductive continuously until the solenoid valve starting current reaches the maximum value based on the output signal of the solenoid valve, and making the driving transistor conductive when the holding current decreases to a minimum value;
1. A current control device for a solenoid valve, comprising a logic operation circuit that generates a signal that makes the driving transistor non-conductive when the solenoid valve holding current increases to a maximum value. 2. A solenoid valve, a driving transistor connected in series to the solenoid valve, a current detection resistor connected to the emitter side of the driving transistor, a freewheel diode connected in parallel to the solenoid valve, and a freewheel diode connected in series with the solenoid valve. a back electromotive force absorption circuit including a control transistor; a first comparator that uses the output signal of the current detection resistor as a comparison input and has a comparison level corresponding to the maximum value of the solenoid valve starting current; and an output of the current detection resistor. an integrator circuit connected to the end of the integrator circuit, and a second integrator circuit having comparison levels corresponding to the maximum and minimum values of the solenoid valve holding current, with the output signal of the integrator circuit as the input to be compared.
a comparator, a control signal that determines the opening time width of the solenoid valve, and a signal that continuously conducts the driving transistor until the solenoid valve starting current reaches a maximum value during the solenoid valve starting period based on the outputs of the two comparators; Then, during the solenoid valve holding period after the solenoid valve starting current attenuates, when the solenoid valve holding current decreases to a minimum value, the driving transistor is made conductive, and when the solenoid valve holding current increases to a maximum value, the driving transistor is turned on. The control transistor is operated in an active region when the solenoid valve starting current is attenuated by a logic operation circuit that generates a signal to make it non-conductive, the output signal of the second comparator, and a control signal that determines the opening time width of the solenoid valve. 1. A current control device for a solenoid valve, comprising a back electromotive force absorption control circuit that causes the solenoid valve to operate in a saturation region during a holding period.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8987579A JPS5614668A (en) | 1979-07-17 | 1979-07-17 | Current controller for solenoid valve |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8987579A JPS5614668A (en) | 1979-07-17 | 1979-07-17 | Current controller for solenoid valve |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5614668A JPS5614668A (en) | 1981-02-12 |
| JPS6327598B2 true JPS6327598B2 (en) | 1988-06-03 |
Family
ID=13982932
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8987579A Granted JPS5614668A (en) | 1979-07-17 | 1979-07-17 | Current controller for solenoid valve |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5614668A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11115798B2 (en) | 2015-07-23 | 2021-09-07 | Irobot Corporation | Pairing a beacon with a mobile robot |
| US11278173B2 (en) | 2002-01-03 | 2022-03-22 | Irobot Corporation | Autonomous floor-cleaning robot |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5813133A (en) * | 1981-07-18 | 1983-01-25 | Hitachi Ltd | Injector driving circuit |
| JPS5851233A (en) * | 1981-09-21 | 1983-03-25 | Hitachi Ltd | Fuel injection valve driving circuit |
| JPS5937476U (en) * | 1982-09-03 | 1984-03-09 | 油研工業株式会社 | Proportional solenoid valve drive circuit |
| US4479161A (en) * | 1982-09-27 | 1984-10-23 | The Bendix Corporation | Switching type driver circuit for fuel injector |
| JPH0779212B2 (en) * | 1985-07-17 | 1995-08-23 | エスエムシ−株式会社 | Power amplifier for solenoid proportional control valve |
| JPH0632534Y2 (en) * | 1987-12-17 | 1994-08-24 | 三國工業株式会社 | Solenoid valve drive circuit |
| US5347419A (en) * | 1992-12-22 | 1994-09-13 | Eaton Corporation | Current limiting solenoid driver |
-
1979
- 1979-07-17 JP JP8987579A patent/JPS5614668A/en active Granted
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11278173B2 (en) | 2002-01-03 | 2022-03-22 | Irobot Corporation | Autonomous floor-cleaning robot |
| US11115798B2 (en) | 2015-07-23 | 2021-09-07 | Irobot Corporation | Pairing a beacon with a mobile robot |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5614668A (en) | 1981-02-12 |
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