GB2135795A

GB2135795A - A rolling control apparatus for an engine

Info

Publication number: GB2135795A
Application number: GB08403081A
Authority: GB
Inventors: Sunao Chikamori; Hideyuki Iwata; Naotake Kumagai; Yoji Ito; Minoru Tatemoto; Tokushige Inuzuka; Hiroyuki Shinoda; Hatsuo Sugiura
Original assignee: Mitsubishi Motors Corp
Current assignee: Mitsubishi Motors Corp
Priority date: 1983-02-09
Filing date: 1984-02-06
Publication date: 1984-09-05
Also published as: GB8403081D0; FR2540587A1; DE3404593A1; GB2135795B; FR2540587B1

Abstract

When a change in operating mode of an automatic transmission is detected by a detector (33), a solenoid drive circuit (30) for changing the damping characteristics of a shock absorbing apparatus (Fig. 6), which limits rolling of the engine, is driven for a predetermined period of time. When the solenoid drive circuit (30) is driven, a solenoid (29) is energized to rotate a spool (25) of the shock absorbing apparatus. The size of the orifice (23) between two liquid-filled chambers (12, 13) is thereby changed to increase the damper effect. As a result, the reaction force against a large torque generated by vehicle engine when the operating mode changes is decreased, and vibration transmitted to a body frame is damped. <IMAGE>

Description

SPECIFICATION A rolling control apparatus for an engine The present invention relates to a rolling control apparatus for an engine, which electronically performs roll control of a vehicle engine.

Recently, automatic transmission vehicles have prevailed. In a vehicle of this type, torques, generated by the power device, differ in an idling or steady drive state and an automatic gear changing state of the automatic transmission. In the idling or steady drive state, a high-frequency and small-magnitude signal is generated, so that a low torque is generated from the power device. However, in the automatic gear changing state, a low-frequency and largemagnitude signal is generated, so that a high torque is generated.

In a vehicle generating different torques, shock absorbing members, as shown in Figure 1, having a nonlinear spring characteristic are conventionally disposed between the engine and vehicle body, so as to decrease transmission of the torque (vibration) to the body frame and provide a comfortable drive.

The shock absorbing member has an inner cylinder a and an outer cylinder b, as shown in Figure 2. A rubber plate c is disposed to couple the inner cylinder a and the outer cylinder b. The inner cylinder a is fixed on the engine, and the outer cylinder b is fixed on the body frame, so that the rubber plate c absorbs the shock. However, in a large engine which generates a large torque, the vibration or shock cannot be absorbed by only the rubber plate c. When an automatic gear change occurs, shock occurs. In order to absorb such a shock, as shown in Figure 3, liquid chambers f and g are formed by upper and lower mount rubber members d and e. An orifice h is formed between the liquid chambers f and g. Aportion i is fixed on the body frame and a portion j is mounted on the engine. The shock is absorbed by utilizing a damping force generated when the liquid passes through the orifice h.When vibration having a large magnitude occurs, the damping force occurs by an action between the liquid and the orifice h. However, when a small shock or displacement occurs, the liquid does not pass through the orifice h due to the resistance of the orifice h. Therefore, a spring constant is increased, and a transfer force of the shock is increased, resulting in inconvenience.

It is an object of the present invention to provide a rolling control apparatus for electronically controlling rolling at the time when an automatic gear change occurs.

According to the present invention, there is provided a rolling control apparatus for an engine, comprising; detecting means for detecting an automatic gear change; roll controlling means for controlling an engine roll; a drive mechanism for driving said roll controlling means; and a drive circuit for driving the drive mechanism in response to a signal from the detecting means.

This invention can be more fully understood from the following detailed description when taken in conjunction with the accompanying drawings, in which: Figure 1 is a graph showing the characteristics of a conventional shock absorbing member; Figure2 is a sectional view showing the internal construction of the conventional shock absorbing member; Figure 3 is a sectional view showing a conventional liquid sealing type shock absorbing member; Figure 4 is a perspective view showing a conventional supporting apparatus and a conventional shock absorbing apparatus which supports an engine; Figure 5 is a plan view of an engine mounting and a rolling control apparatus according to the present invention; Figure 6 is a sectional view of the rolling control apparatus; Figure 7 is a block diagram of a control circuit for controlling the rolling control apparatus shown in Figure 6;; Figure 8 is a sectional view showing the relationship between an orifice and a rotary spool of the rolling control apparatus according to the present invention; Figures 9A to 9C are sectional views of the rolling control apparatus when taken along the line IX - IX of Figure 8; Figure 10 is a graph showing the relationship between the displacement and the transfer force; Figures 1 hand 11B are plan views showing another rotary spool; Figure 12 is a circuit diagram of a control circuit of a rolling control apparatus according to a second embodiment of the present invention; Figure 13 is a circuit diagram of a control circuit of a rolling control apparatus according to a third embodiment of the present invention;; Figure 14 is a circuit diagram of a control circuit of a rolling control apparatus according to a fourth embodiment of the present invention; Figure 15 is a circuit diagram of a control circuit of a rolling control apparatus according to a fifth embodiment of the present invention; Figure 16 is a circuit diagram of a control circuit of a rolling control apparatus according to a sixth embodiment of the present invention; Figure 17 is a circuit diagram of a control circuit of a rolling control apparatus according to a seventh embodiment of the present invention; Figures 18to 20 show a control circuit and its operation of a rolling control apparatus according to an eight embodiment of the present invention; and Figure 21 is a block diagram of a control circuit of a rolling control apparatus according to a ninth embodiment of the present invention.

Afirst embodiment of the present invention will be described with reference to the accompanying drawings. Figures 4 and 5 show a state wherein a power device 2 is mounted on a body frame 1. In each of Figures 4 and 5, the power device 2 comprises an engine 3 and an automatic gear 5. The engine 3 is supported by first and second shock absorbing apparatuses 7 and 8, an engine mount 6 and a transmission mount 9.

The first and second shock absorbing apparatuses 7 and 8 have the same construction and are exemplified by one of them with reference to Figures 6 to 10.

Referring to Figures 6, reference numeral 10 denotes a casing mounted on the body frame 1. The casing 10 is partitioned by a partition plate 11 into an upper liquid chamber 12 and a lower liquid chamber 13.

Liquid 14 is stored in the upper and lower liquid chambers 12 and 13. The liquid 14 is sealed between an elastic body, such as a rubber member 15, in the upper liquid chamber 12 and a diaphragm 16 in the lower liquid chamber 13. A rubber stopper 17 is integrally formed with the rubber member 15 so as to oppose a ceiling portion 18 of the casing 10. The rubber stopper 17 controls the upward displacement ofthe rubber member 15. Apin 19 extends upward from the rubber member 15. The pin 19 extends through a through hole 20 formed in the ceiling portion 18 of the casing 10 and is fixed on the power device 2. A cover 21 is mounted on the distal end portion of the pin 19. A rubber stopper 22 is adhered to the lower surface of the cover 21 to oppose the ceiling portion 18 and to control the displacement of the cover 21.

An orifice 23 comprising an elongated hole is formed in the partition plate 11 along the direction corresponding to the thickness of the partition plate 11,so as to cause the upper liquid chamber 12 to communicate with the lower liquid chamber 13. The orifice 23 has a crank-like sectional shape, as shown in Figures 8 and 9A to 9C. A bearing hole 24 is formed in a bent portion of the orifice 23 along the longitudinal direction of the plate 11. A rotary spool 25 is rotatably inserted in the bearing hole 24. A valve portion 26 is formed in the shaft of the rotary spool 25 to open/close the orifice 23. The valve portion 26 is constituted by an L-shaped large channel 27 and a small channel 28 communicating therewith.Openings of the large and small channels 27 and 28 are formed on the outer surface ofthe shaft of the rotary spool 25 at angular intervals of 90 degrees, so as to selectively oppose the orifice 23.

The orifice 23 is controlled by the valve portion 26 to be in one of the closed, partially opened, and fully opened states. One of the ends of the rotary spool 25 extends outward from the corresponding end of the partition plate 11 and is connected to a drive source such as a rotary solenoid 29. The rotary solenoid 29 is electrically connected to sensors 33 through a control circuit 32 having a solenoid drive circuit 30 and a logic controller 31. The sensors 33 comprise a throttle opening sensor, an engine pulse sensor, and additional sensors for detecting changes in the operation mode of the automatic transmission 5.

The additional sensors comprise a range-change sensor for detecting a change in range of the automatic transmission, a kick-down sensor for detecting a change in the gear reduction ratio in accordance with the vehicle velocity and the load, and an acceleration sensor for detecting a change in the gear reduction ratio in accordance with a depressed degree of the accelerator pedal. The rangechange sensor detects a gear change from the N or P range to any one of the L, 2, D and R ranges or from the D range to the L or R and vice versa. These sensors detect whether or not there is the possibility of a torque reaction and a torque reaction force, if any.The control circuit 32 controls the rotary solenoid 29 in accordance with the magnitude of the detection signal (torque reaction force), so that the opening of the orifice 23 of the partition plate 11 is controlled,.

In the idling or steady drive state (high-frequency and small-magnitude vibrations), a large torque will not be generated. In this case, the rotary solenoid 29 cannot function. The rotary spool 25 is therefore held in the initial state as shown in Figure 9A, and the orifice 23 communicates with the large channel 27.

Therefore, vibrations transmitted from the power device 2 to the pin 19 are absorbed by the rubber member 15. When the rubber member 15 is deformed downward, the liquid 14 in the upper liquid chamber 12 is guided into the lower liquid chamber 13 through the orifice 23. However, when the rubber member 15 is deformed upward, the liquid 14 in the lower chamber 13 flows into the upper liquid chamber 12 through the orifice 23. Therefore, the vibrations acting on the pin 19, are not absorbed when the liquid 14 flows through the orifice 23. As a result, the vibrations are not transmitted to the body frame 1 through the casing 10.

When a shock (low-frequency and largemagnitude vibration) occurs (i.e., when an automatic gear change is made by the automatic transmission 5), a large reaction force against a large torque is generated. The large reaction force is detected by the sensors 33. The sensors 33 supply detection signals to the control circuit 32. The control circuit 32 controls the rotary solenoid 29 to rotate the spool 25, so that the orifice 23 causes the upper and lower liquid chambers 12 and 13to communicate with each other through the small channel 28, as shown in Figure 9B. Therefore, the vibration, transmitted from the power device 2 to the pin 19, is transmitted to the rubber member 15. The rubber member 15 is greatly deformed so that the liquid 14 in the upper liquid chamber 12 flows through the small channel 28.

Vibration energy, to be transmitted or transferred from the power device 2 to the body frame 1, can be absorbed by an absorbancy A of the rubber member 15, and a damping force B near the orifice 23, as shown in Figure 10. As a result, the rollings of the power device 2 are decreased.

In the first embodiment, the crank-like orifice 23 is formed in the partition plate 11. The L-shaped large channel 27 and the small channel 28 communicating therewith constitute the valve portion 26 formed in the rotary spool 25. However, the present invention is not limited to the above construction. For example, as shown in Figures 1 1A and 11 B, a wide channel 35 and a narrow channel 36 which are perpendicular to each other can be formed in the shaft of a rotary spool 34. In this case, the rotary spool 34 can be rotated through 90 degrees to change the opening of an orifice 37.

According to the first embodiment described above, the damping force automatically changes in accordance with the magnitude of the torque due to a gear change performed by the automatic transmission, the power device 2 can be properly prevented from vibrating the body frame 1 and from bamping to the walls or device in the engine room. When the torque reaction does not change, the shock absorbing apparatuses 7 and 8 are not driven. In spite of this, the vibrations of the power device 2 are absorbed by the engine mount 6 and transmission mount 9, since the mounts 6 and 9 are made of soft rubber. As a result, the vibrations are not transmitted to the body frame 1. This ensures a comfortable driving.

A second embodiment of the present invention will be described with reference to Figure 12.

Referring to Figure 12, solenoid valve signals A and B are, respectively, signals which are supplied to solenoids (x and ss when a gear change is made by an electronic automatic transmission. The electronic automatic transmission performs a gear change in accordance with the states of the solenoid valve signals A and B. For example, when the solenoid valve signals A and B are set at high or H level, the automatic transmission is set at the first gear position. When the signal A is set at low or L level and the signal B is set at H level, the gear is set at the second gear position. When the signals A and B are set at L level, the automatic transmission is set at the third gear position. Finally, when the signal A is set at H level and the signal B is set at L level, the automatic transmission is set at the fourth gear position.In this embodiment, the operation state of the electronic automatic transmission is detected by checking the signal states of the signals A and B. The solenoid valve signal A is supplied to AND gates 41-1 and 41-4 directly and to AND gates 41-2 and 41-3 through an inverter 42. The solenoid valve signal B is supplied to the AND gates 41-1 and 41-2 directly and to the AND gates 41-3 and 41-4 through an inverter 43. Outputs from the AND gates 41-1 to 41-4 are supplied to an OR gate 48 through capacitors 44to 47 respectively. A signal R which is set at a high level in response to the R or reverse position of an selector lever is supplied to the OR gate 48 through a capacitor49. A signal D which goes high in response to the D or drive position of the automatic lever is supplied to the OR gate 48 through a capacitor 50.

Reference numeral 51 denotes an accelerator pedal angle sensor for detecting an angle of the acceler ator pedal. An output from the accelerator pedal angle sensor 51 is supplied to an accelerator de pressing speed detecting circuit 52. The accelerator depressing speed detecting circuit 52 generates a signal of H level when the accelerator depressing speed, which is a rate of change of the accelerator opening, exceeds a predetermined value. For exam ple, when the driver greatly depresses the acceler ator pedal, the circuit 52 generates a signal of H level. The signal from the circuit 52 is supplied to the OR gate 48. An output from the OR gate 48 is supplied to a timer circuit 53. When the timer circuit 53 receives the H level signal, the circuit 53 gener ates a signal of H level for a predetermined period of time.The H level signal from the timer circuit 53 is supplied to a solenoid drive circuit 30. The solenoid drive circuit 30 supplies the solenoid drive signal a to the shock absorbing apparatus 8 (Figure 5), and the solenoid drive signal b to the shock absorbing apparatus 7 (Figure 5). When the H level signal is supplied to the solenoid drive circuit 30, the signals a and b are enabled.

The operation of the control circuit having the arrangement described above according to the second embodiment of the present invention will next be described. After the electronic automatic transmission changes between the first, second, third and fourth gear positions, after the selector level is set at the reverse or drive position, or when the accelerator depressing speed is smaller than the predetermined value, the OR gate 48 receives all L level signals. Forthis reason, the timer circuit 53 receives an L level signal. Therefore, the L level signal is supplied from the timer circuit 53 to the solenoid drive circuit 30. The signals from the solenoid drive circuit 30 become disabled.Under this condition, the orifices 23 of the shock absorbing apparatuses 8 and 7 are fully opened, so that the damper effect for a back-and-forth displacement of the engine 3 is small. As a result, vibrations from the engine 3 are not transmitted to the body frame 1.

On the other hand, when the electronic automatic gearchanges between the first, second, third and fourth gear positions, the H level signal is gated through one of the AND gates 41-1 to 41-4. When the automatic transmission is set in the first gear position, the H level signal is gated through the AND gate 41-1; when the automatic transmission is set in the second gear position, the H level signal is gated through the AND gate 41-2; when the automatic transmission is set in the third gear position, the H level signal is gated through the AND gate 41-3; and when the automatic transmission is set in the fourth gear position, the H level signal is gated through the AND gate 41-4. In any case, the H level signal is supplied to the timer circuit 53. The timer circuit 53 then generates the H level signal for a predetermined period of time.Therefore, the signals a and b generated from the solenoid drive circuit 30 become active or enabled for a predetermined period of time.

In other words, when the electronic automatic transmission changes between the first, second, third and fourth gear positions, the orifices 23 of the shock absorbing apparatuses a and 7 are partially opened. As a result, the damper effect for the back-and-forth displacement of the engine 3 becomes great. The damping forces of the shock absorbing apparatuses 8 and 7 become greater, thereby preventing the engine 3 from rolling greatly against the bodyframe 1 buy a large torque.

When the selector lever changes to the R or D position, the signal R or D goes high. The H level signal is then supplied from the OR gate 48 to the timer circuit 53. Therefore, the timer circuit 53 generates the H level signal for a predetermined period of time. The signals a and b generated from the solenoid drive circuit 30 become enabled for the predetermined period of time. In other words, when the selector lever is changed to the R or D position, the orifices 23 of the shock absorbing apparatuses 8 and 7 are partially opened, thereby increasing the damper effect for the back-and-forth displacement of the engine 3. The damping forces of the shock absorbing apparatuses 8 and 7 are increased, so that the engine 3 can be prevented from rolling due to the reaction force against a large torque generated by the engine 3.

When an accelerator depressing speed is greater than a predetermined value, the accelerator depressing speed detecting circuit 52 generates a signal of H level. The timer circuit 53 generates a signal of H level in response to the H level signal from the detecting circuit 52. The signals a and b generated from the solenoid drive circuit 30 become enabled for the predetermined period of time.

When the accelerator depressing speed reaches a predetermined value, the orifices 23 of the shock absorbing apparatuses 8 and 7 are partially opened.

The damper effect for the back-and-forth displacement of the engine 3 becomes strong. The damping forces of the shock absorbing apparatuses 8 and 7 are increased. As a result, when the accelerator depressing speed exceeds the predetermined value, the power device 2 can be prevented-from rolling due to a large torque generated by the engine 3.

In the second embodiment described above, the power device 2 does not greatly move relative to the body frame 1 and does not bump to the devices within the engine room or the car body, even if a large torque reaction occurs when the selector lever moves to the reverse (R) or drive (D) position, when the automatic gear performs its function, or when the accelerator depressing speed exceeds the predetermined value. As long as the engine torque reaction is small, the shock absorbing apparatuses 7 and 8 are not driven. In spite of this, the vibrations of the power device 2 are absorbed by the engine mount 6 and transmission mount 9 since the mounts 6,9 are made of soft rubber. This ensures a comfortable driving.

A third embodiment of the present invention will be described with reference to Figure 13. Referring to Figure 13, solenoid valve signals A and B are respectively generated from a controller 61 arranged in an electronic automatic transmission. The signals A and B are supplied to solenoids a and (3,respec- tively. The electronic automatic transmission changes in accordance with the states of the solenoid valve signals A and B. For example, when the solenoid valve signals A and B are set at high or H level, the automatic transmission is set at the first gear position. When the signal A is set at low or L level and the signal B is set at H level, the automatic transmission is set at the second gear position.

When the signals A and B are set at L level, the automatic transmission is set at the third gear position. Finally, when the signal A is set at H level and the signal B is set at L level, the automatic transmission is set at the fourth gear position. In this embodiment, the operation state of the electronic automatic transmission is detected by checking the signal states of the signals A and B. The solenoid valve signal A is supplied to AND gates 41-1 and 41-4 directly and to AND gates 41-2 and 41-3 through an inverter 42. The solenoid valve signal B is supplied to the AND gates 41-1 and 41-2 directly and to the AND gates 41-3 and 41-4 through an inverter 43. Outputs from the AND gates 41-1 to 41-4 are supplied to an OR gate 48 through capacitors 44 to 47, respectively.

Reference numeral 51 denotes an accelerator pedal angle sensor for detecting the depressing amount of the accelerator pedal. An output from the sensor 51 is supplied to an accelerator depressing speed detecting circuit 52. The detecting circuit 52 generates a signal of H level when an accelerator depressing speed exceeds a predetermined value. The detailed arrangement of the detecting circuit 52 is the same as that shown in Figure 12. For example, when the driver quickly depresses the accelerator pedal, the detecting circuit 52 generates a signal of H level. This H level signal is supplied to the OR gate 48. An output from the OR gate 48 is supplied to a timer circuit 62. The timer circuit 62 generates a signal of H level of a time duration T2 upon reception of the H level signal from the OR gate 48.The H level signal from the timer 62 is supplied to the solenoid drive circuit 30 through an OR gate 63. The solenoid drive circuit 30 generates the signals a and b to the shock absorbing apparatuses 8 and 7 (Figure 5), respectively. When the solenoid drive circuit 30 receives the H level signal, the signals a and b become active or enabled.

Reference numeral 64 denotes an selector lever of an automatic transmission vehicle. When the selector lever 64 changes to a P (park), R (reverse), N (neutral), D (drive), 2 (second) or L (low) position, a voltage from a battery 65 is applied to a P, R, N, D, 2 or Lterminal. The D and Terminals are grounded through diodes D1 and D2, and a resistor R1. A voltage across the resistor R1 is applied to a timer circuit 67 through an inverter 66. The timer circuit 67 generates a signal of H level for a time duration T1 after it receives the H level signal. An output from the timer 67 is supplied to the OR gate 63. It should be noted that the time duration T1 is equal to or longer than the time duration T2.

The operation of the control circuit according to the third embodiment of the present invention will next be described. After the electronic automatic transmission changes to one of the first to fourth positions or when the accelerator depressing speed is smaller than a predetermined value, a signal of L level is supplied to the OR gate 48, and then a signal of L level is supplied to the timer circuit 67. The timer circuit 67 supplies a signal of L level to the solenoid drive circuit 30 through the OR gate 63. Therefore, the signals a and b generated from the solenoid drive circuit 30 are kept low. However, after the selector lever 64 changes from the neutral (N) position to the reverse (R) or drive (D) position, a signal of H level is supplied to the inverter 66.

Therefore, the timer circuit 67 receives the L level signal. The L level signal is supplied from the timer circuit 67 to the solenoid drive circuit 30 through the OR gate 63. The signals a and b generated from the solenoid drive circuit 30 are kept low or disabled.

In fine, after the electronic automatic transmission changes between the first, second, third and fourth positions, or after the selector lever 64 changes from the N position to the R or D position, the solenoid drive circuit 30 will not be driven. Therefore, the orifices 23 of the shock absorbing apparatuses 8 and 7 are fully opened, so that the damper effect for the back-and-forth displacement of the engine 3 is small, and vibrations from the engine 3 are not transmitted to the body frame 1 through the shock absorbing apparatuses 7 and 8.

However, when the electronic automatic transmission changes between the first, second, third and fourth positions, or the accelerator depressing speed is greater than the predetermined value, the H level signal is supplied to the OR gate 48. This H level signal passes from the OR gate 48 to the timer circuit 62. The timer circuit 62 generates a signal of H level for the time duration T2. The signals a and b generated from the solenoid drive circuit 30 are kept high for the time duration T2. In other words, when the electronic automatic transmission changes between the first, second, third and fourth positions or the accelerator depressing speed exceeds the predetermined value, the orifices 23 of the shock absorbing apparatuses 8 and 7 are partially opened for the time duration T2.For this reason, the damper effect for the back-and-forth displacement of the engine 3 is increased, so the rollings of the engine 3 and the transmission 5 are decreased.

When the selector lever 64 changes to the R or D position, an L level signal is temporarily supplied to the inverter 66. Therefore, the timer circuit 67 receives the H level signal and generates an H level signal for a time duration T1. The signals a and b generated from the solenoid drive circuit 30 become enabled for the time duration T1. In other words, when the selector lever 64 is set in the R or D position, the orifices 23 of the shock absorbing apparatuses 8 and 7 are partially opened. The damper effect for fthe back-and-forth displacement of the engine 3 is increased.

In the above embodiment, when the electronic automatic transmission changes between the first, second, third and fourth positions, or the accelerator depressing speed exceeds the predetermined value, the damping forces of the shock absorbing apparatuses 8 and 7 are increased for the time duration T2.

Similarly, when the selector lever 64 is set in the R or D position, the damping forces of the shock absorbing apparatuses 8 and 7 are increased for the duration time T1 (where T1 is equal to or greater than T2). Therefore, the engine 3 and the transmisson 5 can be prevented from rolling against the body frame 1 due to the reaction force against a large torque.

A fourth embodiment of the present invention will be described with reference to Figure 14. Referring to Figure 14, solenoid valve signals A and B are respectively generated from a controller 61 arranged in an electronic automatic transmission. The signals A and B are supplied to solenoids a and , respectively. The electronic automatic transmission changes in accordance with the states of the solenoid valve signals A and B. For example, when the solenoid valve signals A and B are set at high or H level, the automatic transmission is set at the first gear position. When the signal A is set at low or L level and the signal B is set at H level, the automatic transmission is set at the second gear position.

When the signals A and B are set at L level, the automatic transmission is set at the third gear position. Finally, when the signal A is set at H level and the signal B is set at L level, the automatic transmisson is set at the fourth gear position. In this embodiment, the operation state of the electronic automatic transmission is detected by checking the signal states of the signals A and B. The solenoid valve signal A is supplied to AND gates 41-1 and 41-4 directly and to AND gates 41-2 and 41-3 through an inverter 42. The solenoid valve signal B is supplied to the AND gates 41-1 and 41-2 directly and to the AND gates 41-3 and 41-4 through an inverter 43. Outputs from the AND gates 41-4 are supplied to an OR gate 48 through capacitors 44 to 47, respectively. Reference numeral 51 denotes an accelerator pedal angle sensor for detecting the depressing amount of the accelerator pedal.An output from the sensor 51 is supplied to an accelerator depressing speed detecting circuit 52. The detecting circuit 52 generates a signal of H level when an accelerator depressing speed exceeds a predetermined value. For example, when the driver quickly depresses the accelerator pedal, the detecting circuit 52 generates a signal of H level.

Reference numeral 64 denotes an selector lever of an automatic transmission vehicle. When the selector lever 64 changes to R (reverse), D (drive), 2 (second) or L (low) position, a voltage from a battery 65 is applied to an R, D, 2 or L terminal. The D and R terminals are grounded through diodes D1 and D2 and a resistor R1. A voltage across the resistor R1 is applied to a timer circuit 53 through an inverter 66 and the OR gate 48. The timer circuit 53 generates a signal of H level for a predetermined time duration after it receives the H level signal. An output from the timer circuit 53 is supplied to a solenoid drive circuit 30.The solenoid drive circuit 30 supplies the signals a and b to the shock absorbing apparatuses 8 and 7 (Figure 5), respectively.When the solenoid drive circuit 30 receives the H level signal, the signals a and b generated therefrom are enabled.

The operation of the fourth embodiment having the arrangement described above will be described.

After the electronic automatic transmission changes between the first, second, third and fourth gear positions, when the accelerator depressing speed is smaller than the predetermined value, or after the selector lever 64 is set in the reverse (R) or drive (D) position, the OR gate 48 receives a signal of L level.

The timer circuit 53 supplies a signal of L level to the solenoid drive circuit 30. The signals a and b generated from the solenoid drive circuit 30 are kept low or disabled. In this manner, after the electronic automatic transmission changes, between the first, second, third and fourth gear positions, when the accelerator depressing speed is smaller than the predetermined value, or after the selector lever 64 is set in the reverse (R) or drive (D) position, the solenoid drive circuit 30 will not be generated.

Therefore, the orifices 23 of the shock absorbing apparatuses Sand 7 are fully opened. The damper effect for the back-and-forth displacement of the engine 3 is decreased, and vibrations of the engine 3 are not transmitted to the body frame 1 through the shock absorbing apparatuses 8 and 7.

However, when the electronic automatic transmission changes between the first, second, third and fourth gear positions, when the accelerator depressing speed is greater than the predetermined value, or when the selector lever 64 is set in the reverse (R) or drive (D) position, the orifices 23 of the shock absorbing apparatures Sand 7 are partially opened.

Therefore, the damper effect for the back-and-forth displacement of the engine 3 is increased, and the rollings of the power device 2 are increased.

Afifth embodiment of the present invention will be described with reference to Figure 15. Reference numeral 71 denotes a battery; and 72, an IG (ignition) switch. A series circuit of a brake switch 73 and a brake lamp 74 is connected to a terminal IG of the IG switch 72. The brake switch 73 is closed when a brake pedal (not shown) is depressed, and the brake lamp 74 is turned on. The common node between the brake switch 73 and the brake lamp 74 is connected to one terminal of a relay coil 75P. . The other terminal of the relay coil 75t is grounded. A relay switch 75s is closed when the relay coil 75I is energized. The relay switch 75s is also closed in response to the brake switch 73.A voltage V1 (e.g., 8 V) is applied to one terminal of the relay switch 75s through a resistor R1 The common node between the resistor R1 and the relay switch 75s is connected to a timer circuit 53 through an inverter 76. The timer circuit 53 generates a signal of H level for a predetermined period of time after it reaches the H level signal. The output from the timer circuit 53 is supplied to a solenoid drive circuit 30. The solenoid drive circuit 30 generates the signals a and b which are respectively supplied to the shock absorbing apparatuses 8 and 7 (Figure 5). When the solenoid drive circuit 30 receives the H level signal, it generates the signals a and b of H level.

The operation of the fifth embodiment having the arrangement described above will be described. The driver turns on the IG switch 72 to close the terminal IG. At the same time, the driver depresses the accelerator pedal (not shown) to start the engine. In this case, when the driver does not depress the brake pedal, the brake switch 73 is opened. In response to this switching state, the relay switch 75s is also opened. The voltage V1 (i.e., H level signal) is applied to the inverter 76, so that the timer circuit 53 receives the L level signal. The timer circuit 53 then supplies an L level signal to the solenoid drive circuit 30. The signals a and b generated from the solenoid drive circuit 30 are kept disabled.The orifices 23 of the shock absorbing apparatuses 8 and 7 are fully opened, so that the damper effect for the back-andforth displacement of the engine 3 is decreased, vibrations of the engine 3 are not transmitted to the bodyframe 1.

Assume that the driver depresses the brake pedal.

In this case, the brake switch 73 is closed. For this reason, the excitation current flows through the relay coil 75, and the relay switch 75s is closed. A ground potential (L level) is applied to the inverter 76, so that the timer circuit 53 receives the H level signal. The output from the timer circuit 53 is kept at H level for a predetermined period of time. The signals a and b generated from the solenoid drive circuit 30 become enabled for the predetermined period of time. In this manner, when the driver depresses the brake pedal, the orifices 23 of the shock absorbing apparatuses 8 and 7 are partially opened, so that the damper effect for the back-andforth displacement of the engine 3 is increased.

In the above embodiment, since the damping forces of the shock absorbing apparatuses 8 and 7 are increased for the predetermined period of time after the driver depresses the brake pedal, the displacement of the engine due to the inertia force can be prevented.

A sixth embodiment of the present invention will be described with reference to Figure 16. Referrina to Figure 16, reference numeral 81 denotes an electronic fuel injection control apparatus for performing optimum fuel injection in accordance with the operating state of the vehicle. Reference numeral 82 denotes an air cleaner; 83, an air flow sensor arranged in the air cleaner 82 to detect an intake air flow rate; 84, an engine; 85, a fuel tank; and 86, a microcomputer. The airflow sensor 83 measures the intake airflow rate by utilizing von Karman's vortex street. The number of pulses generated from the air flow sensor 83 changes in accordance with the intake air amount. A signal representing the number of pulses is supplied from the airflow sensor 83 to the microcomputer 86 and a frequency-voltage converter 87.This converter 87 generates a voltage corresponding to the frequency of the input signal.

Therefore, the converter 87 generates the voltage corresponding to the intake air amount. The voltage signal from the converter 87 is compared by a comparator 88 with a reference voltage. The comparator 88 generates a signal of H level when the input voltage is higher than the reference voltage. An output from the comparator 88 is supplied to the timer circuit 53. The timer circuit 53 generates the H level signal for the predetermined period of time after it receives the H level signal. The output from the timer circuit 53 is supplied to the solenoid drive circuit 30. The solenoid drive circuit 30 generates the signals a and b which are respectively supplied to the shock absorbing apparatuses 8 and 7 (Figure 5).

When the solenoid drive circuit 30 receives the H level signal, the signals, a and b generated therefrom are enabled.

The operation of the sixth embodiment having the arrangement described above will be described. The intake air amount is detected by the airflow sensor 83 of the electronic fuel injection control apparatus 81. The signal representing the intake air amount is converted by the converter 87 to a voltage corresponding to the frequency of the input signal. The voltage signal corresponding to the intake air amount is supplied from the converter 87 to the comparator 88. When the voltage signal has a level lowerthan a predetermined level (i.e., when the intake air amount is smaller than a predetermined amount), the comparator 88 generates a signal of L level, so that the timer circuit 53 generates a signal of L level. The signals a and b generated from the solenoid drive circuit 30 are disabled. Therefore, when the intake air amount is smaller than the predetermined value, the orifices 23 of the shock absorbing apparatuses 8 and 7 are fully opened, so that the damper effect for the back-and-forth dis placement of the engine 3 is decreased.

On the other hand, when the intake air amount exceeds the predetermined value, the comparator 88 generates a signal of H level, so that the output from the timer circuit 53 is set at H level for a predetermined period of time. As a result, the signals a and b generated from the solenoid drive circuit 30 are enabled. That is, when the intake air amount exceeds the predetermined value, the orifices 23 of the shock absorbing apparatuses 8 and 7 are partially opened, and the damper effect for the back-and-forth displacement of the engine 3 is increased.

In the above embodiment, when the intake air amount exceeds the predetermined value, the damper effect of the shock absorbing apparatuses 8 and 7 is increased. However, the damper effect of the shock absorbing apparatuses 8 and 7 can be increased when a change in intake air amount exceeds a predetermined value.

In the above embodiment, when the intake air amount or its change exceeds the corresponding value, the damping forces of the shock absorbing apparatuses 8 and 7 are increased for the predetermined period of time. Therefore, even when the intake air amount is increased, an undesirable displacement of the engine 3 due to the torque reaction can be properly prevented.

A seventh embodiment of the present invention will be described with reference to Figure 17.

Referring to Figure 17, solenoid valve signals A and B are signals which are respectively supplied to solenoids a and P for performing a gear change under the control of an electronic automatic transmission. The electronic automatic transmission changes in accordance with the states of the solenoid valve signal A and B. For example, when the solenoid valve signals A and B are set at high or H level, the automatic transmission is set at the first gear position. When the signal A is set at low or L level and the signal B is set at H level, the automatic transmission is set at the second gear position.

When the signals A and B are set at L level, the automatic transmission is set at the third gear position. Finally, when the signal A is set at H level and the signal B is set at L level, the automatic transmission is set at the fourth gear position. In this embodiment, the operation state of the electronic automatic transmission is detected by checking the signal states of the signals A and B. The solenoid valve signal A is supplied to AND gates 41-1 and 41-4 directly and to AND gates 41-2 and 41-3 through an inverter 42. The solenoid valve signal B is supplied to the AND gates 41-1 and 41-2 directly and to the AND gates 41-3 and 41-4 through an inverter 43. Outputs from the AND gates 41-1 to 41-4 are supplied to a NOR gate 91 through capacitors 44 to 47, respectively. Reference numeral 92 denotes an ignition coil; 93, a contact point provided in a distributor; and 94, a spark plug.A high voltage is applied to the spark plug 94, and a spark discharge occurs. In this embodiment, the rpm of the engine is detected by a signal generated upon opening/closing of the contact point 93. The signal generated between the ignition coil 92 and the contact point 93 is supplied to an engine revolution detecting circuit 95 for generating a voltage corresponding to the rpm of the engine. The detecting circuit 95 comprises a waveshaping circuit 96, a waveform re-forming circuit 97 for setting a pulse width to be a predetermined width, a low-pass filter 98 and a comparator 99. The wave-shaping circuit 96 performs wave-shaping such as elimination of a noise component from a voltage pulse signal having the number of pulses corresponding to the number of revolutions of the engine.The waveform re-forming circuit 97 sets the pulse signal from the wave-shaping circuit 96 to be the predetermined width. A signal from the waveform re-forming circuit 97 is supplied to the low-pass filter 98. The low-pass filter 98 supplies to the comparator 99 a voltage signal which corresponds to the number of revolutions of the engine. The comparator 99 generates a signal of H level when the number of revolutions of the engine is less than a predetermined number (e.g., 1,500 rpm). The output from the engine revolution detecting circuit 95 is also supplied to the base of a transistor 100 whose emitter is grounded. The collector of the transistor 100 is coupled to a NOR gate 101. An output from the NOR gate 91 is also supplied to the NOR gate 101.

Therefore, the output from the transistor 100 is set at L level when the engine revolution number is less than 1,500 rpm.

Reference numeral 64 denotes an selector lever of an automatic transmission. When the selector lever 64 is changed over, voltage is applied from the battery 65 to one of the P, R, N, D, 2 and Terminals through a key switch 72. The R, N and D terminals are grounded through the diodes D1 to D3, a capacitor C1 and a resistor R1. A potential, across the resistor R1, is supplied to an OR gate 103 through an inverter 102. The OR gate 103 also receives the output from the NOR gate 101. When the selector lever 64 is set in any one of the R, N and D positions, the voltage (H level signal) is applied from the battery 65 to one end of the resistor R1. For this reason, the output from the inverter 102 is set at L level.

Reference numeral 51 denotes an accelerator pedal angle sensor for detecting the depressing amount of the accelerator pedal. An output from the sensor 51 is supplied to an accelerator depressing speed detecting circuit 52. The detecting circuit 52 generates a signal of L level when an accelerator depressing speed exceeds a predetermined value.

When the driver quickly depresses or releases the accelerator pedal, the detecting circuit 52 generates the L level signal. The output from the detecting circuit 52 is supplied to the NOR gate 101.

The output from the OR gate 103 is supplied to a timer circuit 67. When the timer circuit 67 receives the H level signal, it generates a signal of H level for a time duration Ti. The output from the timer circuit 67 is supplied through an OR gate 104 to a solenoid drive circuit 105 which comprises power transistors Q1 and Q2. The collector of the transistor Q2 is connected to the rotary solenoid 29 (Figure 8) for partially opening the orifices of the shock absorbing apparatuses 8 and 7.

The output from the timer circuit 67 is supplied to a timer circuit 62 through an inverter 106 which comprises a transistor Q3. When the timer circuit 62 receives an H level signal, it generates a signal of H level during a time duration T2. The output from the timer circuit 62 is supplied to one input terminal of an AND gate 107. A pulse signal is supplied from an oscillator (not shown) to the other input terminal of the AND gate 107. The pulse width of the pulse signal, generated from this oscillator, is narrower than those of the signals generated from the timer circuits 67 and 62. The output from the AND gate 107 is supplied to the OR gate 104.

The operation of the seventh embodiment, arranged as described above, will be described.

When the electronic automatic transmission changes between the first, second, third and fourth positions, the L level signal is gated through the NOR gate 91. When the accelerator depressing speed exceeds a predetermined value, the accelerator depressing speed detecting circuit 52 generates a signal of L level. When the revolution number of the engine is less than 1,500 rpm, the transistor 100 generates a signal of L level. Therefore, when the electronic automatic transmisson changes between the first, second, third and fourth positions, when the accelerator depressing speed exceeds the predetermined value, and when the engine revolution number is less than 1,500 rpm, all input signals to the NOR gate 101 are set at L level. For this reason, the output from the NOR gate 101 is set at H level.

Therefore, the timer circuit 67 receives the H level signal and generates a signal of H level for the time duration T1. Therefore, the solenoid drive circuit 105 is enabled for the time duration T1. The rotary solenoid 29 is energized to rotate the rotary spool 25.

The orifices 23 of the shock absorbing apparatuses 8 and 7 are partially opened. Therefore, the damper effect for the back-and-forth displacement of the engine 3 is increased.

On the other hand, after the signal, generated from the timer circuit 67, is set at H level during the time duration Tithe output therefrom goes down. In response to this operation, the timer circuit 62 generates a signal of H level for a time duration T2.

The pulse signal, generated from the oscillator, is supplied to the solenoid drive circuit 105 through the AND gate 107 and the OR gate 104 forthe time duration T2. The solenoid drive circuit 105 performs the ON/OFF operation, so that a shock, acting on the solenoid at the time when the damper effect is decreased, can be eliminated, and thereby prevent noise.

In this embodiment, when the electronic automatic transmission changes, when the accelerator depressing speed exceeds the predetermined value, and when the engine revolution number is less than the predetermined rpm, the damping forces of the shock absorbing apparatuses 8 and 7 are increased, thereby preventing the back-and-forth displacement of the engine 3 due to a largetoque reaction.

An eight embodiment of the present invention will be described with reference to Figures 18 to 20.

Referring to Figure 18, reference numeral 111 denotes a potentiometer for detecting a throttle valve opening (i.e., the accelerator pedal angle). A detection signal, representing the throttle valve opening, is supplied to a throttle opening/closing velocity detecting circuit 112 for detecting the opening/ closing velocity of the throttle valve. The detecting circuit 112 generates a signal of H level when the throttle valve is opened to a size largerthan a predetermined size. The detection signal from the potentiometer 111 is also supplied to a throttle opening detecting circuit 113 for detecting whether or not the throttle opening is less than a predetermined value. The detecting circuit 113 generates a signal of L level when the throttle opening is less than the predetermined value.Reference numeral 114 denotes a revolution sensor for detecting an engine revolution number. The detection signal, representing the engine revolution number, is supplied from the sensor 114 to an engine revolution detecting circuit 115 for detecting whether or not the revolution number is less than a predetermined value. The detecting circuit 115 generates a signal of L level when the revolution number is less than the predetermined value. The outputs from the detecting circuits 113 and 115 are supplied to an OR gate 116. Reference numeral 117 denotes a gear change detecting circuit for receiving gear change signals A and B from an electronic automatic gear (not shown) and for detecting, in accordance with the gear change signals A and B, whether or not the gear changes.More specifically, the detecting circuit 117 detects whether or not the gear changes to one of the first to fourth positions. If this occurs, the detecting circuit 117 generates a signal of H level.

The output signals from the OR gate 116 and the detecting circuit 117 are supplied to an AND gate 118. Reference numeral 1 19R denotes an R range position switch which is turned on when an selector lever (not shown) is set in the reverse or R position; and 119D, a D range position switch which is turned on when the selector lever is set in the drive or D position. Outputs from the R and D range position switches 1 19R and 1 19D are supplied to an inhibitor switch ON/OFF detecting circuit 119. The detecting circuit 119 generates a signal of H level every time one of the Rand D position switches 11 9R and 1 19D is turned on/off. Reference numeral 120 denotes an external control switch which is turned on in the case of testing the shock absorbing apparatuses 8 and 7.

An operation signal of the external control switch 120 is supplied to an input interface circuit 121. The input interface circuit 121 generates a signal of H level when the external control switch 120 is turned on. The outputs from the detecting circuit 112, the AND gate 118, the detecting circuits 119, and the interface circuit 121 are gated through an OR gate 121 and are supplied to a timer circuit 53. The timer circuit 53 controls and drives a solenoid drive circuit 30 for a predetermined period of time when the circuit 53 receives the H level signal. The output from the interface circuit 121 is also supplied to a chopper circuit 122. The chopper circuit 122 performs chopping action at the trailing edge of the timer pulse generated from the timer circuit 53. The chopper circuit 122 stops chopping action every time the output from the input interface circuit 121 increases.

An output from the solenoid drive circuit 30 is coupled to one end of a rotary solenoid 29 for causing the shock absorbing apparatus 8 and 7 to increase the damper effect. The other end of the solenoid 29 is coupled to the positive terminal of a battery 71. The negative terminal of the battery 71 is grounded. The output from the solenoid drive circuit 30 is supplied to a high temperature detecting circuit 123. The detecting circuit 123 detects a decrease in current flowing in the solenoid drive circuit 30 when the solenoid 29 is heated to a high temperature. The detecting circuit 123 supplies a signal of L level to the timer circuit 53 only when the solenoid current is less than a predetermined value. When the L level signal is supplied from the detecting circuit 123 to the timer circuit 53, the timer is forcibly stopped.

The positive terminal of the battery 71 is connected, through a key switch 72, to a stable power supply circuit 124 and a low voltage detecting circuit 125. An output from the detecting circuit 125 is coupled to the timer circuit 53. When the power supply voltage of the stable power supplying circuit 124 becomes less than a predetermined value, the timer of the timer circuit 53 will not start.

Figure 19 is a circuit diagram showing the detailed configuration of the circuit shown in Figure 18.

The operation of the ninth embodiment, arranged as described above, will be described. A voltage, generated from the potentiometer 111, will increase/ decrease in accordance with the accelerator pedal depression. The detecting circuit 112 detects whether or not the opening/closing speed of the throttle opening, detected by the potentiometer 111, is greater than the predetermined value. When the opening/closing velocity exceeds the predetermined value, the detecting circuit 112 generates the H level signal. As a result, the timer circuit 53 is started to drive the solenoid drive circuit 30 for the predetermined period of time. The solenoid 29 is then energized and the rotary spool 25 is started. The orifices 23 of the shock absorbing apparatuses 8 and 7 are partially opened, so that the damper effect for the back-and-forth displacement of the engine 3 is increased.

It will now be described how the shock absorbing apparatuses 8 and 7 is driven when the electronic automatic transmission changes. The gear change signals A and B, generated from the electronic automatic transmission, are supplied to the detecting circuit 117. The detecting circuit 117 detects, in accordance with the gear change signals A and B, whether or not the automatic transmission changes to one of the first to fourth positions. When the automatictransmission changes to one ofthefirstto fourth positions, the detecting circuit 117 generates the H level signal.

When the detecting circuit 113 detects that the throttle opening is greater than the predetermined value or the detecting circuit 115 detects that the engine revolution number exceeds the predetermined value, the detecting circuit 113 or 115 generates an H level signal. For this reason, the electronic automatic transmission changes. Furthermore, when the throttle opening or the engine revolution number exceeds the corresponding predetermined value, the H level signal is supplied from the AND gate 118 to the timer circuit 53. Therefore, the solenoid drive circuit 30 is driven for the predetermined period of time. The solenoid 29 is accordingly energized, and the rotary spool 25 is rotated. The orifices 23 of the shock absorbing apparatuses 8 and 7 are partially opened, so that the damper effect for the back-and-forth displacement of the engine 3 is increased.

On the other hand, when the throttle opening is less than the corresponding predetermined value and the engine revolution number is also less than the corresponding predetermined value, the OR gate 116 generates an L level signal. For this reason, even if the electronic automatic transmission changes, the AND gate 118 generates an L level signal. As a result, the timer circuit 53 will not start. In other words, even if the electronic automatic transmission changes, the damper effectforthe back-and-forth displacement of the engine 3 will not be increased under the conditions that the engine revolution number and the throttle opening are less than the predetermined values, respectively.

Every time the R range position switch 1 19R or the D range position switch 1 19D is turned on/off, the inhibitor switch ON/OFF detecting circuit 119 generates an H level signal. This H level signal is supplied to the timer circuit 53, and the solenoid drive circuit 30 is operated for a predetermined period of time.

For this reason, the solenoid 29 is energized for the predetermined period of time, and the rotary spool 25 is rotated. The orifices 23 of the shock obsorbing apparatuses 8 and 7 are partially opened, so that the damper effect for the back-and-forth displacement of the engine 3 (i.e., a rolling) is increased.

In order to forcibly actuate the shock absorbing apparatuses 8 and 7 in a test, the external control switch 120 is turned on. The input interface circuit 121 generates the H level signal which is supplied to the timer circuit 53. The solenoid drive circuit 30 is operated for a predetermined period of time in response to the H level signal from the timer circuit 53. Therefore, the solenoid 29 is energized for the predetermined period of time, and the rotary spool 25 is rotated. As a result, the damper effect for the engine 3 is increased. As is apparent from Figure 19, when the external control switch 120 is turned on, an output from the chopper circuit 122 is grounded through the input interface circuit 121 and the external control switch 120.The chopping action will not be performed by the chopper circuit 122 in response to the trailing edge of the timer pulse from the timer circuit 53. The timer pulse from the timer circuit 53 goes down, and then the solenoid drive circuit 30 is stopped. The rolling stoppers generate great impact noise by biasing forces of the return springs disposed in the shock absorbing apparatuses 8 and 7. In this manner, the return to the nonoperative state of the shock absorbing apparatuses 8 and 7 can be checked. The mode of operation of the chopper circuit 122 will be described in detail with reference to Figure 19 and Figures 20A and 20B later.

A current flowing through the solenoid 29 is detected to prevent the solenoid 29 from degradation and smoke generation since the solenoid 29 generates excessive heat when the shock absorbing apparatuses 8 and 7 are frequently used. This detection is based on the assumption that the current flowing through the solenoid 29 decreases when a temperature of the solenoid 29 is increased.

A current flowing through the solenoid 29 is supplied to the high temperature detecting circuit 123 through the solenoid drive circuit 30. The detecting circuit 123 detects whether or not the current flowing through the solenoid 29 is decreased. When the current flowing through the solenoid 29 becomes lower than a predetermined value, the detecting circuit 123 forcibly stops the timer circuit 53. The solenoid drive circuit 30 is forcibly stopped in response to the L level signal from the timer circuit 53. As a result, the degradation and smoke generation, with respect to the solenoid 29, can be prevented.

The operation of the chopper circuit 122 will be described with reference to Figure 19 and Figures 20A and 20B. Referring to Figure 19, the chopper circuit 122 supplies a saw-tooth wave signal (indicated by reference symbol a) to the plus (+) terminal of a comparator 53-1 in the timer circuit 53. When the timer circuit 53 is turned off, an input voltage to the minus (-) terminal of the comparator 53-1 is lowered as indicated by a curve b. Therefore, the voltage level of the saw-tooth wave signal, during a period A, is intermittently lowered below the voltage indicated by the curve b. During this period A, the comparator 53-1 generates a signal of L level.

Therefore, during the period A, the solenoid drive circuit 30 can be intermittently driven, as indicated in Figure 20B. By arranging the chopper circuit 122, the solenoid drive circuit 30 can be intermittently driven for the predetermined period of time after the timer circuit 53 is turned off. Therefore, even after the timer circuit 53 is turned off, the impact noise from the stoppers, which is generated by the biasing forces of the return springs in the shock absorbing apparatuses 8 and 7, can be prevented.

A ninth embodiment of the present invention will be described with reference to Figure 21. Referring to Figure 21, reference numeral 131 denotes: a "2" position switch which is turned on when the driver sets an selector lever (not shown) in the 2 position; 132, an "L" position switch which is turned on when the driver sets the selector lever in the low or L position. Outputs from the "2" and "L" position switches 131 and 132 are supplied to one input terminal of an AND gate 135 through a low-pass filter 133 and a wave-shaping circuit 134. When the driver sets the selector lever in the low or second position, a signal of H level is supplied to the one input terminal of the AND gate 135 through the low-pass filter 133 and the wave-shaping circuit 134.

Reference numeral 136 denotes a potentiometer for detecting a throttle opening determined by an accelerator pedal angle. A detection signal corresponds to the throttle opening and is supplied from the potentiometer 136 to a throttle opening velocity detecting section 139, a throttle closing velocity detecting section 140 and a throttle opening detecting section 141 through a low-pass filter 137 and an amplifier circuit 138. The detecting sections 139 and 141 respectively generate signals of H level when the throttle opening velocity exceeds predetermined values; The threshold value of the detecting section 139 is smaller than that of the detecting section 141.

For example, the threshold value of the detecting section 139 is set to be 3 m/s, while the threshold value of the detecting section 141 is set to be 5 m/s.

The detecting section 140 generates a signal of H level when the throttle closing velocity exceeds a predetermined value. An output from the detecting section 139 is supplied to the other input terminalof the AND gate 135. An output from the detecting section 141 is supplied to one input terminal of an AND gate 142.

Reference numeral 143 denotes: a "D" position switch which is turned on when the driver sets the selector lever in the drive or D position; and 144, an "R" position switch which is turned on when the driver sets the selector lever in the reverse or R position. A signal from the "D" position switch 143 is supplied to the other input terminal of the AND gate 142 through a low-pass filter 145 and a waveform re-forming circuit 146. In practice, when the driver sets the selector lever in the drive or D position, a signal of H level is supplied to the other input terminal of the AND gate 142 through the low-pass filter 145 and the waveform re-forming circuit 146. A signal from the "R" position switch 144 is supplied to a "D" rangel"R" range judging section 149 through a low-pass filter 147 and a waveform re-forming circuit 148.Every time the "D" position switch 143 or the "R" position switch 144 is turned on/off, the judging section 149 generates a signal of H level.

On the other hand, the gear change signals A and B are generated by an electronic automatic transmission (not shown) and are supplied to a gear change judging section 152 through a low-pass filter 150 and a waveform re-forming circuit 151. The judging section 152 detects whether or not a gear change occurs in accordance with the gear change signals A and B. More particularly, the judging section 152 detects whether or not the automatic transmission changes between the first, second, third and fourth positions. If a gear change is detected, the judging section 152 generates a signal of H level. This H level signal is supplied to an OR gate 153. The OR gate 153 also receives outputs from the AND gate 135, the detecting section 140, the judging section 149, and the AND gate 142. An H level signal is then gated through the OR gate 153 and is supplied to the timer circuit 53. When the timer circuit 53 receives the H level signal, it supplies the H level signal to the solenoid drive circuit 30 for a predetermined period of time, so that the solenoid drive circuit 30 is driven for the predetermined period of time. The solenoid drive circuit 30 then controls the solenoid 29 for adjusting the size of orifices of the shock absorbing apparatuses 8 and 7.

The operation of the ninth embodiment, having the arrangement described above, will be described hereafter. A voltage generated from the potentiometer 136 is increased when the driver gradually depresses the accelerator pedal. Avoltage, corresponding to the throttle opening determined by the accelerator pedal angle, is supplied from the potentiometer 136 to the detecting sections 139 and 141 through the low-pass filter 137 and the amplifier circuit 138. Assuming that the driver sets the selector lever in the second or low position, the H level signal is then supplied to the one input terminal of the AND gate 135. When the throttle opening velocity exceeds 3 m/s, an ANDed output is obtained from the AND gate 135 and is supplied as the H level signal to the timer circuit 53.On the other hand, when the driver sets the selector lever in the drive position, the H level signal is supplied to the one input terminal of the AND gate 142. When the throttle opening velocity exceeds 5 m/s, an ANDed output is obtained from the AND gate 142 and is supplied as the H level signal to the timer circuit 53. As a result, the timer circuit 53 causes the solenoid drive circuit 30 to operate for a predetermined period of time. The solenoid 29 is energized for the predetermined period of time, and the rotary spool 25 is rotated. The orifices 23 of the shock absorbing apparatuses 8 and 7 are partially opened, so that the damper effect for the back-and-force displacement of the engine 3 is increased.

When the driver releases the accelerator pedal, a voltage corresponding to the throttle opening is supplied from the potentiometer 136 to the detecting section 140 through the low-pass filter 137 and the amplifier circuit 138. When the throttle opening velocity exceeds a reference velocity, the detecting section 140 supplies the H level signal to the timer circuit 53. As a result, the timer circuit 53 causes the solenoid drive circuit 30 to operate for the predetermined period of time. The solenoid 29 is then energized for the predetermined period of time, so that the rotary spool 25 is rotated in response to the energization of the solenoid 29. The orifices 23 of the shock absorbing apparatuses 8 and 7 are partially opened, and the damper effect for the back-and-forth displacement of the engine 3 is increased.

Every time the "D" position switch 143 or the "R" position switch 144 is turned on/off, the judging section 149 generates the H level signal which is then supplied to the timer circuit 53. As a result, the timer circuit 53 causes the solenoid drive circuit 30 to operate for the predetermined period of time. The solenoid 29 is then energized for the predetermined period of time, and the rotary spool 25 is rotated in response to the energization of the solenoid 29. The orifices 23 of the shock absorbing apparatuses 8 and 7 are partially opened, so that the damper effect for the back-and-forth displacement of the engine 3 is increased.

Meanwhile, the gear change signals A and B are generated by the electronic automatic transmission and are supplied to the judging section 152 through the low-pass filter 150 and the waveform re-forming circuit 151. The judging section 152 detects whether or not a gear change occurs in accordance with the gear change signals A and B. More particularly, the judging section 152 detects whether or not the automatic transmission changes between the first, second, third and fourth positions. If a gear change is detected, the judging section 152 generates a signal of H level. As a result, the timer circuit 53 causes the solenoid drive circuit 30 to operate for the predetermined period of time. The solenoid 29 is then energized for the predetermined period of time, and the rotary spool 25 is rotated in response to the energization of the solenoid 29. The orifices 23 of the shock absorbing apparatuses 8 and 7 are partially opened, so that the damper effect for the back-andforth displacement of the engine 3 is increased.

The rolling control apparatus shown in Figure 21 is the type in which the shock absorbing apparatuses 8 and 7 are driven to avoid the rolling of the engine when the throttle opening velocity exceeds a reference value. The reference value is changed when the selector lever is moved from position D to position L or 2, or vice versa. The reference value for position D is greater than that for position L or 2. Therefore, the rollings of the engine body 3 and transmission 5, which are caused by the torque reaction, are effectively absorbed even when the selector lever is in position, L or 2, and the engine speed is thus greatly increasing.

Claims

1. A rolling control apparatus for an engine, comprising: detecting means for detecting a change in an operation mode of an automatic transmission; roll controlling means for controlling rolling of the engine; a drive mechanism for driving said roll controlling means; and a drive circuit for driving said drive mechanism in response to a signal from said detecting means.

2. A rolling control apparatus, according to claim 1, wherein said roll controlling means comprises: a casing for storing a liquid; a partition memberfixed on one of the engine our a vehicle body to partition said casing into two liquid chambers; a mounting memberfor mounting a wall of said casing which opposes said partition member on the other one of the engine or the vehicle body; orifice units having an orifice formed in said partition member to cause said liquid chambers to communicate with each other and a rotary spool for adjusting an orifice opening; and a drive unit for rotating said rotary spool.

3. A rolling control apparatus, according to claim 1, wherein said apparatus comprises detecting means for detecting that said automatic transmission is set in one of the drive and reverse positions; and drive mechanism being operated by said drive circuit for a predetermined period oftime in response to a signal from said detecting means.

4. A rolling control apparatus, according to claim 1, wherein said apparatus comprises detecting means for detecting that said automatic transmission is set in one of the drive and reverse positions and is subjected to a gear change, said drive mechanism being operated by said drive circuit for a predetermined period of time in response to a signal from said detecting means.

5. A rolling control apparatus, according to claim 4, wherein said apparatus comprises velocity measuring means for detecting whether or not a value corresponding to an accelerator depressing speed exceeds a predetermined value; said drive mechanism being operated by said drive circuit for a predetermined period of time in response to a signal from one of said detecting means and said velocity measuring means.

6. A rolling control apparatus, according to claim 5, wherein said drive mechanism is driven by said drive circuit, under the control of a timer circuit, for a period T1 when said detecting means detects that said automatic transmission is set in one of the drive and reverse positions, and for a period T2, under the control of a timer circuit, when said detecting means detects that said automatic transmission is set in one of the drive and reverse positions or said velocity measuring means detects that the value corresponding to the accelerator depressing speed exceeds the predetermined value.

7. A rolling control apparatus, according to claim 5, wherein said apparatus comprises a brake switch which is turned on upon depression of a brake pedal; said drive mechanism being operated by said drive circuit for a predetermined period of time in response to a signal from one of: said brake switch, said detecting means and said velocity measuring means.

8. A rolling control apparatus, according to claim 5, wherein said apparatus comprises velocity measuring means for detecting a change in an intake airflow rate; said drive mechanism being operated by said drive circuit for a predetermined period of time in response to a signal from said velocity measuring means.

9. A rolling control apparatus, according to claim 1, wherein said apparatus comprises detecting means for detecting a change in said automatic transmission and velocity measuring means for detecting whether or not a value corresponding to an accelerator depressing speed exceeds a predetermined value; said drive mechanism being operated by said drive circuit for a predetermined period of time in response to a signal from one of said detecting means and said velocity measuring means.

10. A rolling control apparatus, according to claim 9, wherein said apparatus comprises engine revolution measuring means for detecting whether or not an engine revolution number is less than a reference revolution number; said drive mechanism being operated by said drive circuit for a predetermined period of time in response to a signal from one of: said detecting means, said velocity measuring means, and said engine revolution measuring means.

11. A rolling control apparatus, according to claim 1, wherein said apparatus comprises detecting means for detecting a change in said automatic transmission, engine revolution measuring means for detecting whether or not an engine revolution number is less than a reference revolution number, and inhibiting means for inhibiting the supply of a signal from said detecting means to said drive circuit in response to a signal from said engine revolution measuring means; said drive mechanism being operated by said drive circuit for a predetermined period of time.

12. A rolling control apparatus, according to claim 1, wherein said apparatus comprises detecting means for detecting a change in said automatic transmission, opening measuring means for detecting whether or not a value corresponding to an accelerator pedal angle is less than a predetermined value, and inhibiting means for inhibiting supply of a signal from said detecting means to said drive circuit in response to a signal from said opening measuring means; said drive mechanism being operated by said drive circuit for a predetermined period of time.

13. A rolling control apparatus, according to claim 1, wherein said apparatus comprises detecting means for detecting whether or not said automatic transmission is set in one of the drive and low positions, first velocity measuring means for detecting whether or not a value corresponding to an accelerator depressing speed exceeds a reference value, and second velocity measuring means for detecting whether or not the value corresponding to the accelerator depressing speed exceeds a preset value lower than the reference value; said drive mechanism being operated by said drive circuit for a predetermined period of time when said detecting means detects that said automatic transmission is set in the drive position and said first velocity measuring means generates a signal, or when said detecting means detects that said automatic transmission is set in the low position and said second velocity measuring means generates a signal.

14. A rolling control apparatus for an engine, substantially as herein before described with reference to Figures 5 to 21 of the accompanying drawings.