JPH0211782B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a negative pressure control valve, and particularly to a negative pressure control valve that converts an electrical signal into negative pressure.

[Prior Art] In exhaust gas recirculation control and air-fuel ratio control of vehicle engines, a negative pressure control valve is used to convert the magnitude of current, which is a control signal, into the magnitude of negative pressure, which is control operating fluid pressure. Needed.

This type of negative pressure control valve includes a casing having a negative pressure inlet port and a negative pressure outlet port, and a casing that is provided in the casing and cooperates with the casing to connect the negative pressure inlet port and the negative pressure to one side thereof. a diaphragm defining a diaphragm chamber including an extraction port and having an atmospheric port for opening the diaphragm chamber to the atmosphere; carried by the diaphragm and opening the negative pressure introduction port when the diaphragm is in a first position; a valve element that closes the atmospheric port and closes the negative pressure introduction port and opens the atmospheric port when the diaphragm is in a second position displaced from the first position to the one side; and a valve element that linearly displaces the quantity of electricity. a linear motion electromagnetic device for converting a quantity into a linear motion electromagnetic device, and is directly coupled to the linear motion electromagnetic device by a force generated in its moving core depending on the magnitude of the current supplied to the electromagnetic coil by the linear motion electromagnetic device. Japanese Patent Laid-Open No. 54-57227 proposes a negative pressure control valve configured to bias the diaphragm from the second position toward the first position.

[Problems to be Solved by the Invention] The negative pressure control valve having the above configuration is capable of operating as a linear solenoid within the range of the magnitude of the negative pressure supplied to the negative pressure introduction port, regardless of fluctuations in the negative pressure. This has the advantage that a negative pressure corresponding to the magnitude of the current supplied to the electromagnetic coil can be extracted from the negative pressure extraction port. However, since the moving core of a linear motion electromagnetic device is usually made of a magnetic material such as iron that has a fairly large mass, in the above configuration in which the moving core is directly connected to the diaphragm and moves as one, The mass of the moving body increases during the vibratory reciprocating motion of the diaphragm for controlling negative pressure while alternately opening and closing the negative pressure introduction port and the atmospheric port, and the opening and closing of the ports are performed at fine intervals. In particular, hunting may occur in control during transitions when changing the negative pressure value, and control responsiveness may deteriorate.

SUMMARY OF THE INVENTION In view of the above-mentioned problems with the known negative pressure control valves, it is an object of the present invention to provide a negative pressure control valve that is improved in this respect.

[Means for Solving the Problems] In order to solve the problems, the present invention provides a casing having a negative pressure introduction port and a negative pressure extraction port, and a casing provided in the casing and cooperating with the casing. a diaphragm that defines a diaphragm chamber including the negative pressure inlet port and the negative pressure outlet port on the side thereof and has an atmospheric port for opening the diaphragm chamber to the atmosphere; When the diaphragm is in a second position displaced from the first position to the one side, the negative pressure introduction port is opened and the atmospheric port is closed. a valve element that opens;
In a negative pressure control valve having a linear motion electromagnetic device that converts an amount of electricity into a linear displacement amount, a spring is provided that biases the diaphragm in a direction from the second position toward the first position, It is proposed that the spring is received between the diaphragm and the mover of the linear motion electromagnetic device.

According to the configuration of the negative pressure control valve according to the present invention as described above, the force that biases the diaphragm in the direction from the second position to the first position is applied by one spring, and this spring is applied to the diaphragm. Since the magnitude of the applied spring force is controlled by the linear motion type electromagnetic device, the inertial mass moving with the diaphragm is kept at a small value, and the negative pressure due to the oscillatory reciprocating motion of the diaphragm can be quickly controlled. Therefore, a negative pressure control valve with high responsiveness can be obtained.

[Example] The present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a longitudinal sectional view showing one embodiment of a negative pressure control valve according to the present invention. The negative pressure control valve has a cylindrical casing 1, and the casing is composed of a solenoid cover 2, a valve chamber member 3, and an end cover 4 that are fastened to each other. A diaphragm 5 is installed in the casing 1 at the joint between the valve chamber member 3 and the end cover 4, and the diaphragm works with the solenoid cover 2 on one side of the diaphragm, that is, upward in the figure. room 6
and on the other side, i.e., downward in the figure, cooperate with the end cover 4 to define an atmosphere opening chamber 7, respectively. The atmosphere open chamber 7 is opened to the atmosphere through a hole 8 provided in the end cover 4. An air filter 9 is attached to the hole 8. A tube member 10 is arranged in the center of the diaphragm chamber 6, and this tube member 10 is fixed to the solenoid cover 2, and opens into the diaphragm chamber 6 at one end and outside the casing 1 at the other end. Negative pressure introduction port 1
1. Further, a negative pressure outlet port 12 communicating with the diaphragm chamber 6 is formed in the valve chamber member 3 .

The diaphragm 5 has a valve support member 1 at its central portion.
It carries 3. The valve supporting member 13 has a chamber 1 therein.
4, and this chamber 14 communicates with the diaphragm chamber 6 through a hole 15 on one side and with the atmosphere open chamber 7 through a hole 16 on the other side. A valve element 17 is provided within the chamber 14 so as to be movable in the axial direction of the casing 1, that is, in the vertical direction in the figure. The valve element 17 is compressed by the helical compression spring 1 when the diaphragm 5 is in the position shown (first position).
Due to the spring force of 8, one end surface of the chamber 14 comes into contact with the valve seat 19, thereby closing the hole 15. Further, when the diaphragm 5 is in the first position, the valve element 17 faces the one end of the tube member 10 with a relatively small gap therebetween, and opens the negative pressure introduction port 11.

Linear solenoid 2 is inside solenoid cover 2.
0 is configured. The linear solenoid 20 is
A cylindrical electromagnetic coil 21 and a stator core 22 fixed to the solenoid cover 2, and a bush 24 attached to the guide shaft portion 23 of the stator core 22.
It has a cylindrical moving core (movable element) 25 that can be moved vertically in the figure while being guided by the solenoid cover 2, and a yoke member 26 fixed to the solenoid cover 2. The moving core 25 is urged downward as shown in the figure by the spring force of a compression coil spring 29 attached between a spring receiver member 27 fixedly attached to the tip of the moving core 25 and a spring receiver member 28 fixed to the solenoid cover 2. has been done.

The linear solenoid 20 is excited by the current supplied to the electromagnetic coil 21, and the solenoid cover 2,
A line of magnetic force is generated passing through the yoke member 26, the moving core 25, and the stator core 22, and the moving core 25 is driven upward in the figure against the action of the compression coil spring 29 in accordance with the current supplied to the electromagnetic coil 21. It's summery.

A compression coil spring 30 is resiliently mounted between the valve support member 13 and the spring receiving member 27. The compression coil spring 30, together with the valve support member 13, urges the diaphragm 5 downward in the figure.

The compression coil spring 18 is constituted by a spring with a very small spring constant, so that the valve element 17
is driven in accordance with the balanced relationship between the spring force applied by the compression coil spring 30 to the diaphragm 5 and the force applied to the diaphragm 5 due to the pressure difference between the diaphragm chamber 6 and the atmosphere open chamber 7, and due to the pressure difference. When the force is less than the spring force of the helical compression spring 30, in other words when the negative pressure in the diaphragm chamber 6 is low, the diaphragm 5 is in the first position as shown and the valve element 17 is seated on the valve seat 19. The communication between the diaphragm chamber 6 and the atmosphere open chamber 7 is cut off, and the negative pressure introduction port 11 is opened toward the inside of the diaphragm chamber 6 at a distance from the tip of the tube member 10. On the other hand, when the force applied to the diaphragm 5 due to the pressure difference is larger than the spring force of the compression coil spring 30, in other words, the diaphragm chamber 6
When the negative pressure inside is large, the diaphragm 5 is displaced upward as shown in the figure while deflecting the compression coil spring 30, and the valve element 17 comes into contact with the tip of the pipe member 10 to close the negative pressure introduction port 11 and close the valve The diaphragm chamber 6 and the atmosphere release chamber 7 are communicated apart from the seat 19, and the negative pressure in the diaphragm chamber 6 is bled out.

By operating the valve element 17 as described above,
The negative pressure inside the diaphragm chamber 6 is supplied by a compression coil spring 30.
is maintained at a value corresponding to the spring force applied to the diaphragm 5. The spring force of the compression coil spring 30 becomes larger as the movable spring receiving member 27 is located lower in the figure, and on the contrary, it becomes smaller as the movable spring receiving member 27 is located higher in the figure. Since the movable spring receiving member 27 is connected to the moving core 25 and moves upward in the figure according to the current applied to the electromagnetic coil 21, the equilibrium value of this valve device becomes smaller as the current applied to the electromagnetic coil 21 increases. Become,
The stable value of the negative pressure in the diaphragm chamber 6 becomes smaller accordingly. As a result, the negative pressure that decreases as the current applied to the electromagnetic coil 21 increases is extracted from the negative pressure extraction port 12.

FIG. 2 shows another embodiment of the negative pressure control valve according to the present invention. In FIG. 2, parts corresponding to those in FIG. 1 are designated by the same reference numerals as in FIG. In the embodiment shown in FIG. 2, the moving core 25 is driven downward in the figure in response to an increase in the current applied to the electromagnetic coil 21, so as to increase the spring force of the compression coil spring 30. The moving core 25 is attached to a bush 24 attached to the inner circumference of the electromagnetic coil 21.
It is designed to move up and down in the figure as shown in the figure.

In this embodiment, the equilibrium value of the valve system increases as the current supplied to the electromagnetic coil 21 increases.

Further, FIG. 3 shows still another embodiment of the negative pressure control valve according to the present invention. In this embodiment, the casing 50 of the negative pressure control valve includes a solenoid cover 51, an end cover 52, and an end cap 5.
3. A diaphragm 54 is mounted in the casing 50 at the joint between the end cover 52 and the end cap 53, and the diaphragm 54 cooperates with the end cap 53 on one side, that is, upwardly in the figure, to open the diaphragm chamber. 55, and on the other side, i.e., downwardly in the figure, cooperate with the end cover 52 to define an atmosphere opening chamber 56, respectively. The atmosphere open chamber 56 communicates with a chamber 59 inside the end cover 52 through a hole 57 provided in the end cover 52 and an air filter 58 . The chamber 59 is open to the atmosphere through an opening not shown. A negative pressure inlet port 60 and a negative pressure outlet port 61 are formed in the end cap 53 . The negative pressure introduction port 60 connects a chamber 62 formed in the end cap 53 and the end cap 53.
It communicates with the diaphragm chamber 55 through a pipe member 63 attached to the diaphragm chamber 55, and the negative pressure outlet port 61 directly communicates with the diaphragm chamber 55.

Diaphragm 54 carries a valve carrier member 64 in its central portion. The valve carrier member 64 communicates with the diaphragm chamber 55 through a hole 66 on one side and with the atmosphere opening chamber 56 through a hole 67 on the other side. A valve element 68 is provided within the chamber 65 so as to be movable in the axial direction of the casing 50, that is, in the vertical direction in the figure. When the diaphragm 54 is in the position shown, the valve element 68 is brought into contact with a valve seat 70 formed by one end surface of the chamber 65 by the spring force of a compression coil spring 69, thereby closing the hole 66. Valve element 68 also faces the distal end of tube member 63 with a relatively small gap when diaphragm 54 is in the position shown, opening tube member 63 to diaphragm chamber 55.

A compression coil spring 71 is installed between the valve support member 64 and the end cap 53, and the compression coil spring 71 urges the diaphragm 54 downward in the drawing together with the valve support member 64. Inside the solenoid cover 51 is a linear solenoid 7 that is substantially the same as the linear solenoid shown in FIG.
2 are configured. The linear solenoid 72 is
It has a cylindrical electromagnetic coil 73 and a stator core 74 fixed to the solenoid cover 51, a moving core 75 that is movable in the vertical direction in the figure, and a yoke member 76 fixedly attached to the solenoid cover 51. There is. A shaft 77 is fixedly attached to the moving core 75.
is engaged with the stator core 74 so as to be movable in the axial direction thereof. The moving core 75 is guided by a shaft 77 and a bush 78 fixed to a yoke member 76, and moves in the vertical direction in the figure.

A spring receiving member 79 is fixed to the tip of the shaft 77, and a compression coil spring 81 is provided between this spring receiving member 79 and a spring receiving member 80 fixed to the solenoid cover 51. The spring 81 urges the moving core 75 upward in the figure. The compression coil spring 82 is configured with a spring having a smaller spring force than the compression coil spring 71.

The linear solenoid 72 is excited by the current supplied to the electromagnetic coil 73 to form lines of magnetic force passing through the end cover 52, yoke member 76, moving core 75, and stator core 74, and the moving core 75 is driven downward in the figure against the action of the compression coil spring 81.

Further, another spring receiving member 83 is provided in the chamber 59 of the end cover 52, and a compression coil spring 82 is attached between this spring receiving member 83 and the spring receiving member 79. Spring receiving member 8
3 passes through a through hole 85 provided in the end cover 52 with a shaft portion 84 provided in the center, and engages with the valve support member 64 at its tip, thereby applying the spring force of the compression coil spring 82 to the valve. It is adapted to be transmitted to the carrier member 64.

The compression coil spring 69 is constituted by a spring with a very small spring constant, and therefore the valve element 68
Substantially, the spring force applied to the diaphragm 54 by the compression coil spring 71, the spring force applied to the diaphragm 54 by the compression coil spring 82, and the force applied to the diaphragm 54 due to the pressure difference between the diaphragm chamber 55 and the atmosphere opening chamber 56. When the force due to the pressure difference is smaller than the difference between the spring force of the compression coil spring 74 and the spring force of the compression coil spring 82, in other words, when the negative pressure in the diaphragm chamber 55 is small. , the diaphragm 54 is in the position as shown, and the valve element 68 is seated on the valve seat 70 to cut off communication between the diaphragm chamber 55 and the atmosphere release chamber 56, and is spaced apart from the tube member 63 and connected to the negative pressure introduction port. 60 is open toward the diaphragm chamber 55. On the other hand, when the force applied to the diaphragm 54 due to the pressure difference is larger than the difference between the spring force of the compression coil spring 71 and the spring force of the compression coil spring 82, that is, the diaphragm chamber 55
When the negative pressure inside is large, the diaphragm 54 moves upward in the figure, and the valve element 68 contacts the pipe member 63 to close the negative pressure introduction port 60, and moves away from the valve seat 70 to open the diaphragm chamber 55 to the atmosphere. It communicates with the chamber 56 and bleeds the negative pressure in the diaphragm chamber 55.

By operating the valve element 68 as described above,
The negative pressure inside the diaphragm chamber 55 is supplied by the compression coil spring 7.
1 and the spring force applied to the diaphragm 54 by the compression coil spring 82. Compression coil spring 7
The spring force exerted by the compression coil spring 82 on the diaphragm 54 is substantially constant, but the spring force exerted on the diaphragm 54 by the compression coil spring 82 is determined by the axial position of the spring receiving member 79. The more the spring is located, the lower the spring force becomes, and the difference in the spring force becomes larger. In other words, the lower the spring receiving member 79 is, the greater the effective spring force of the compression coil spring 71 becomes, and the valve element 68 increases accordingly.
The equilibrium value of becomes large, and the stable value of the negative pressure in the diaphragm chamber 55 becomes large. Since the spring bearing member 79 lowers as the current applied to the electromagnetic coil 73 by the moving core 75 increases, the equilibrium value of the valve element increases as the current applied to the electromagnetic coil 73 increases. Therefore, negative pressure corresponding to the current applied to the electromagnetic coil 73 is extracted from the negative pressure extraction port 61.

In each of the embodiments described above, the spring receiving member 27 or 79 is driven by a linear solenoid, but the present invention is not limited to this, and the spring receiving member can be driven by a linear motor or the like. It may also be driven by other linear motion electromagnetic devices.

In the negative pressure control valve according to the present invention, the negative pressure is controlled according to the balanced relationship between the spring force applied to the diaphragm by the spring whose spring force is changed by the linear motion electromagnetic device and the force applied to the diaphragm by the negative pressure. Because of this, the amount of bleed air is smaller than the solenoid valve type or linear solenoid valve type negative pressure control valves mentioned above, and as a result, the cleaning cycle of the air filter built into the valve device is faster than the conventional one. It is longer than , and has less negative pressure loss.
When a vacuum pump is used as the negative pressure source, the capacity of the vacuum pump can be made smaller than that of the conventional vacuum pump.
Furthermore, compared to a solenoid-type negative pressure control valve using duty ratio control, the number of switching operations of the valve element is reduced, thereby improving the operational durability of the valve device.
Further, since the negative pressure is adjusted according to the balance of forces acting on the diaphragm, more accurate negative pressure control can be performed than with a linear solenoid valve type negative pressure control valve.

[Brief explanation of drawings]

FIG. 1, FIG. 2, and FIG. 3 are longitudinal sectional views each showing an embodiment of a negative pressure control valve according to the present invention. 1...Casing, 2...Solenoid cover,
3... Valve chamber member, 4... End cover, 5... Diaphragm, 6... Diaphragm chamber, 7... Atmospheric release chamber, 8... Hole, 9... Air filter, 10...
... Pipe member, 11 ... Negative pressure introduction port, 12 ... Negative pressure extraction port, 13 ... Valve support member, 14 ...
Chamber, 15, 16... Hole, 17... Valve element, 18...
... Compression coil spring, 19 ... Valve seat, 20 ... Linear solenoid, 21 ... Electromagnetic coil, 22 ... Stator core, 23 ... Guide shaft section, 24 ... Bush, 25 ... Moving core, 26 ... Yoke Member, 27, 28... Spring receiving member, 29, 30...
...Compression coil spring, 50...Casing, 51...
... Solenoid cover, 52 ... End cover, 5
3... End cap, 54... Diaphragm,
55...Diaphragm chamber, 56...Atmospheric release chamber,
57...hole, 58...air filter, 59...
Chamber, 60... Negative pressure introduction port, 61... Negative pressure outlet port, 62... Chamber, 63... Pipe member, 64...
Valve supporting member, 65...chamber, 66, 67...hole, 6
8...Valve element, 69...Compression coil spring, 70...
... Valve seat, 71 ... Compression coil spring, 72 ... Linear solenoid, 73 ... Electromagnetic coil, 74 ... Stator core, 75 ... Moving core, 76 ...
Yoke member, 77...shaft, 78...button, 7
9, 80... Spring receiving member, 81, 82... Compression coil spring, 83... Spring receiving member, 84... Shaft portion, 85... Through hole.

Claims (1)

[Claims] 1. A casing having a negative pressure introduction port and a negative pressure extraction port, and a diaphragm chamber provided in the casing that cooperates with the casing and includes the negative pressure introduction port and the negative pressure extraction port on one side thereof. a diaphragm having an atmospheric port for opening the diaphragm chamber to the atmosphere; a valve element that closes the negative pressure introduction port and opens the atmospheric port when the diaphragm is in a second position displaced from the first position toward the one side; and a linear motion electromagnetic device that converts an amount of electricity into a linear displacement amount, and the spring is provided between the diaphragm and the mover of the linear motion electromagnetic device. A negative pressure control valve characterized by receiving.