JPH0515549Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Purpose of invention]

(Industrial Application Field) This invention relates to a negative pressure control device for an actuator used, for example, in an automatic vehicle speed control device that automatically controls the traveling speed of a vehicle to a certain set value. (Prior Art) Conventionally, for example, there has been a negative pressure control device for an actuator as described above, as shown in FIG. That is, in the figure, a coil spring 100d is provided in a negative pressure chamber 100c formed by a diaphragm 100a and a casing 100b, and the repulsive force of the coil spring 100d causes the output wire 1 to move when the negative pressure in the negative pressure chamber 100c decreases.
00e to the left in the figure and moves the output wire 100e to the right in the figure when negative pressure increases, and the output wire 100e, which is the output end, is connected to a throttle valve of the engine (not shown). . Reference numeral 101 denotes a negative pressure control device, which includes a vacuum pump 102, an air valve 103, and a release valve 104. One end of the air valve 103 and the release valve 104
One end of each is connected to a reduced pressure chamber 102a of the vacuum pump 102 and to a negative pressure chamber 100c of the actuator 100, respectively. The other end of the air valve 103 and the other end of the release valve 104 are opened to the atmosphere via filters 103a and 104a. In the actuator negative pressure control device 101 having such a structure, when the actuator 100 is operated to control the traveling speed of the vehicle to a set value, for example, when the set value is larger than the traveling speed of the vehicle, In response to a signal from a controller (not shown), the air valve 103 and the relief valve 104 are closed, and the vacuum pump 102 is activated. Then, the pressure in the decompression chamber 102a of the vacuum pump 102 is lowered, and the output wire 100e of the actuator 100 is lowered.
is sucked in the right direction in the figure to increase the traveling speed of the vehicle, and when the traveling speed of the vehicle is synchronized with the set value, the vacuum pump 10 is stopped. In addition, if the set value is small compared to the traveling speed of the vehicle, the air valve 103 is opened to the atmosphere while the vacuum pump 102 is stopped.
When the output wire 100e of the actuator 100 is returned to the left in the figure by the repulsive force of the coil spring 100d and tuned to the set value, the air valve 103 is closed. When the negative pressure control device of this actuator 100 is not used, the air valve 103
and the release valve 104 are opened to the atmosphere, and the output wire 10 of the actuator 100 is
0e is returned to the neutral position. (Problem to be Solved by the Invention) However, in the conventional negative pressure control device for an actuator as described above, the exhaust pressure generated when the vacuum pump 102 is operated is released to the atmosphere by the discharge valve 102b of the vacuum pump 102. As a result, there were problems in that the exhaust pressure was wasted and a considerable amount of dust in the atmosphere could be sucked in, causing trouble in the operation of the actuator 100. Also, when considering the return force of the actuator 100, it is found that the return force is obtained from the difference between the pressure in the negative pressure chamber 100c of the actuator 100 and the atmosphere and the return elastic force of the coil spring 100d. In order to return the throttle valve reliably, it is necessary to use a coil spring 100d with a large set pressure in order to obtain a larger return force. There is a problem in that the negative pressure required for operation becomes large, resulting in a large loss when the vacuum pump 102 is depressurized, and that a load is placed on the vacuum pump 102. (Purpose of the invention) Therefore, this invention was devised to solve the conventional problems as described above, and it is possible to prevent the pressure discharged from the vacuum pump from being wasted and to prevent the return of the actuator. The purpose of this invention is to provide a negative pressure control device for an actuator that can be quickly and reliably controlled, and its structure has been specially devised.

[Structure of the idea]

(Means for Solving the Problems) The negative pressure control device for an actuator according to this invention includes an actuator having an atmospheric chamber and a negative pressure chamber separated by an actuator diaphragm, and a suction valve communicating with the pressure reducing chamber. and a vacuum pump having a discharge valve and having the decompression chamber communicated with the negative pressure chamber of the actuator via a first communication pipe and a suction valve, one of which is branched from the first communication pipe. a release valve that communicates with the negative pressure chamber of the actuator via a branch pipe; one side of the release valve communicates with the negative pressure chamber of the actuator via a second communication pipe, and the other side of the valve communicates with the negative pressure chamber of the actuator through a filter; an air valve, which has a sealed shape and is connected to the decompression chamber of the vacuum pump through a third communication pipe and the discharge valve on one side, and the release valve through a fourth communication pipe on the other side; It is characterized by having a storage tank connected to the other side, and in an embodiment adopted as necessary, the storage tank is equipped with an internal pressure setting release valve to keep the internal pressure of the tank constant. (Operation of the invention) In the negative pressure control device for an actuator according to this invention, in the vacuum pump, the suction valve is
Because the discharge valve is connected to the negative pressure chamber of the actuator through the second communication pipe, and the discharge valve is connected to the storage tank through the second communication pipe, the discharge pressure from the pressure reduction chamber is connected to the atmosphere through a closed circuit. Not open. Also,
When the vacuum pump is operating, the storage tank stores air under positive pressure while the release valve is closed, and stores negative pressure in the actuator when the release valve opens. Since air under positive pressure is transferred to the chamber, the time for the negative pressure level in the negative pressure chamber to drop is short. (Example) Hereinafter, an example of the negative pressure control device for an actuator according to this invention will be described based on the drawings. <Embodiment 1> FIG. 1 shows a negative pressure control device for an actuator according to an embodiment of this invention. That is, in the negative pressure control device 1 shown in the figure,
2 is a vacuum pump, 3 is an air valve, 4 is a release valve, 5 is a closed storage tank in this embodiment, and 6 is a sealed storage tank.
is an actuator operated by this negative pressure control device 1. In the vacuum pump 2, a motor 2a is operated by a signal from a controller (not shown) to reciprocate a diaphragm 2b, and when the diaphragm 2b moves back, that is, when moving downward in FIG. 1, the suction valve 2c is opened. When the diaphragm 2b moves forward, that is, when moving upward in FIG. 1, the discharge valve 2e is opened to discharge the gas from the pressure reducing chamber 2d, thereby reducing the pressure. The suction valve 2c communicates with the inside of the negative pressure chamber 6a provided in the actuator 6 via the first communication pipe 8, and the discharge valve 2e communicates with the inside of the storage tank 5 via the third communication pipe 11. is connected to. Similarly to the vacuum pump 2, the air valve 3 is configured such that a solenoid 3a is energized and demagnetized by a signal from a controller (not shown) to open and close a valve 3b. An opening 3c for venting to the atmosphere is provided at one end on the lower side in the figure, and a filter 3d is attached to this opening 3c, and the other end on the upper side in the figure is connected to a second communication pipe 9. It communicates with the negative pressure chamber 6a of the actuator 6 via. On the other hand, in the release valve 4, like the air valve 3, a solenoid 4a is excited and demagnetized by a signal from a controller (not shown) to open and close a valve 4b. In the figure, one end on the lower side communicates with the inside of the storage tank 5 via the fourth communication pipe 12, and the other end on the upper side in the figure is a branch branched from the first communication pipe 8. Negative pressure chamber 6 of actuator 6 via pipe 10
a, and the suction valve 2c of the vacuum pump 2
It communicates with the decompression chamber 2d via. On the other hand, the storage tank 5 is hermetically sealed in this embodiment, with a part communicating with one end of the release valve 4 and the other part communicating with the third communication pipe 11 and the discharge of the vacuum pump 2. It communicates with a decompression chamber 2d via a valve 2e. The actuator 6 forms a negative pressure chamber 6a and an atmospheric chamber 6f divided inside the casing 6c by an actuator diaphragm 6b.
A coil spring 6d is provided within this negative pressure chamber 6a. When the negative pressure level in the negative pressure chamber 6a increases due to the operation of the vacuum pump 2, the actuator diaphragm 6b is moved toward the negative pressure chamber 6a against the elastic force of the coil spring 6d, and this actuator diaphragm 6b is moved toward the negative pressure chamber 6a side. The opening of the throttle valve 7 of the engine is increased by suctioning the output wire 6e connected to the yuator diaphragm 6b. In the negative pressure control device 1 for the actuator 6 having the above configuration, the engine throttle valve 7
When operating the actuator 6 connected via the output wire 6e to control the traveling speed of the vehicle to a set value, for example, if the traveling speed of the vehicle (actual vehicle speed) is smaller than the set value,
The air valve 3 and the release valve 4 are closed by a signal from a controller (not shown), and the vacuum pump 2 is activated at the same time. Therefore, when the negative pressure level in the negative pressure chamber 6a of the actuator 6 increases due to the operation of the vacuum pump 2, the actuator diaphragm 6b moves rightward in FIG. 1 and sucks the output wire 6e. This results in
When the opening degree of the throttle valve 7 of the engine is increased to increase the running speed of the vehicle and synchronize it to the set value, the vacuum pump 2 is stopped by a signal from a controller (not shown) and the vehicle is caused to auto-cruise. . At this time, since the vacuum pump 2 operates with the release valve 4 closed, positive pressure air is stored inside the storage tank 5. In addition, in this state, the traveling speed of the vehicle (actual vehicle speed)
becomes larger than the set value, the release valve 4 is opened for a predetermined period of time in response to a signal from a controller (not shown), and the positive pressure sealed in the storage tank 5 is released into the negative pressure chamber 6a of the actuator 6.
, the actuator diaphragm 6b is moved to the left in FIG. 1, that is, in the return direction of the actuator 6, and the air valve 3 is opened to the atmosphere for a predetermined time by a signal from a controller (not shown). The inside of the negative pressure chamber 6a of the actuator 6 was synchronized with the atmosphere, and the actuator diaphragm 6b was moved to the left in FIG. 1 by the repulsive force of the coil spring 6d of the actuator 6, and synchronized with the set value. by the way,
Close the air valve 3 and release valve 4. Thereby, the opening degree of the throttle valve 7 of the engine is reduced in a short period of time to reduce the speed of the vehicle, and when the speed of the vehicle is synchronized to the set value, the vehicle is caused to auto-cruise. Furthermore, when auto cruise is turned off by a switch (not shown) or canceled by stepping on a brake pedal, the release valve 4 is fully opened by a signal from a controller (not shown), and storage tank 5
At the same time, the air valve 3 is opened and the atmosphere flows into the pressure chamber 6a of the actuator 6. As a result, the diaphragm 6b of the actuator 6 quickly and reliably returns to the neutral state due to the positive pressure air from the storage tank 5 and the return force of the coil spring 6d, allowing the throttle valve 7 of the engine to return quickly. This will improve responsiveness. <Embodiment 2> FIG. 2 shows another embodiment of the negative pressure control device for an actuator according to this invention. That is, in this case, the storage tank 5 shown in Example 1 is provided with an internal pressure setting release valve 5a that can adjust the positive pressure stored in the storage tank 5 to a constant pressure. That is, by adjusting the maximum value of the positive pressure stored in the storage tank 5, for example, the positive pressure supply at the time of return to the actuator 6 is adjusted to a constant pressure, and the return operation of the actuator 6 is performed. This makes it possible to control the time required for Therefore, in this case, compared to the first embodiment, the return of the actuator 6 can be time-controlled, so that, for example, the throttle valve 7
The closing timing of the door can be controlled by time, allowing for more detailed control.

[Effect of the idea]

As explained above, the actuator negative pressure control device according to this invention does not waste the pressure discharged from the vacuum pump, and allows the actuator to return quickly, compared to conventional devices. This has an excellent effect in that it can be carried out reliably.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of a negative pressure control device for an actuator according to an embodiment of the present invention, FIG. 2 is a schematic sectional view of a negative pressure control device for an actuator according to another embodiment of the invention, and FIG. 3 is a conventional It is a schematic sectional view of a negative pressure control device of an actuator in . 1... Actuator negative pressure control device, 2...
Vacuum pump, 2c...Suction valve, 2d...Decompression chamber, 2e...Discharge valve, 3...Air valve, 3
d...Filter, 4...Release valve, 5...
Storage tank, 6... Actuator, 6a... Negative pressure chamber, 6b... Actuator diaphragm, 6
f...Atmospheric chamber, 8...First communication pipe, 9...Second
10... branch pipe, 11... third communicating pipe, 12... fourth communicating pipe.

Claims (1)

[Claims for Utility Model Registration] (1) An actuator comprising an atmospheric chamber and a negative pressure chamber separated by an actuator diaphragm, an inlet valve and a discharge valve communicating with the decompression chamber, and a first a vacuum pump that communicates the vacuum chamber with the negative pressure chamber of the actuator through a communication pipe and a suction valve; a release valve communicating with the chamber; and an air valve having one end communicating with the negative pressure chamber of the actuator through a second communication pipe and the other end being open to the atmosphere through a filter; a storage tank, the storage tank being in communication with the pressure reducing chamber of the vacuum pump via a third communication pipe and the discharge valve, and the other being communicated with the other of the release valves via a fourth communication pipe. A negative pressure control device for an actuator, characterized in that: (2) The negative pressure control device for an actuator according to claim 1, wherein the storage tank is provided with an internal pressure setting relief valve that keeps the tank internal pressure constant.