JPH0464784A - Liquid pressure control valve device - Google Patents

Abstract

PURPOSE:To prevent nonconformity by vibration of a valve body by forming a constitution that an axial motion position of the valve body is regulated by a liquid pressure applied on one side of the valve body and a drive force from a plunger applied on the other side. CONSTITUTION:An electromagnetic pilot valve 40 is composed of a sleeve 41, an orifice 42 and a needle valve body 43, and a solenoid means 44, and a pilot chamber R0 is formed between it and a valve hole 41 to be connected with a pilot passage 19. The needle valve body 43 controls a flow of actuating oil flowing to a low pressure chamber R1 by axial motion to control a pilot pressure in the pilot chamber R0, and it is pushed left on the back side by a rod 44b of the solenoid means 44. A middle chamber R2 is formed on the back side, and the middle chamber R2 is connected with the low pressure chamber R1 through a connection hole 41b provided at the sleeve 41 and a throttle O2. The solenoid means 44 is composed of a magnetic body core 44a and a rod 44b, a plunger 44c, an electromagnetic coil 44d, a flange 44e, etc.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a valve device used in various hydraulic circuits, and in particular, it is provided with a supply path, a load path, a discharge path, and a pilot path. a pilot pressure control valve for controlling the pressure in the load path by controlling communication with the pilot; The present invention relates to a hydraulic control valve device including an electromagnetic pilot valve that controls pilot pressure applied to a passageway.

BACKGROUND OF THE INVENTION Conventionally, in this type of hydraulic control valve device, nothing is interposed in the outflow path of the electromagnetic pilot valve. (For example, see Utility Application No. 1-214600, etc.) For this reason, if the pyro-nod pressure is controlled to reduce with an electromagnetic pilot valve and the load path of the pressure control valve is connected to the discharge path, the discharge will be discharged from the load path. The liquid discharged into the solenoid pilot valve interferes with the liquid discharged through the outflow passage of the solenoid pilot valve, and the pressure fluctuation caused by this interference is directly transmitted to the valve body of the solenoid pilot valve. This may cause vibrations and produce abnormal noise, and may also have an adverse effect on the pressure reduction control of the pilot pressure by the electromagnetic pilot valve, impairing the responsiveness of the pressure control valve. The present invention has been made to address the above-mentioned problems, and aims to prevent the pressure fluctuations caused by the interference of the liquid mentioned above from being directly transmitted to the valve body of an electromagnetic pilot valve, thereby preventing problems caused by vibration of the valve body. It is an object.

[Means to solve the problem]

In order to achieve the above object, in the present invention, the electromagnetic pilot valve has a pilot chamber formed downstream of the orifice and communicating with the pilot passage, and a pilot chamber communicating with the outflow passage through a communication passage. A valve element that controls the flow rate of liquid flowing into the low pressure chamber by axial movement and forms an intermediate chamber that communicates with the low pressure chamber through a flow passage at the back, and a port that pushes the valve element in the axial direction from the back. a magnetic core having a rod operating hole in the center through which the rod passes; a plunger that faces an end face of the magnetic core and drives the valve body in the axial direction via the rod; the magnetic core and the plunger; a solenoid device including an electromagnetic coil that applies an attractive magnetic field between them, and a connection path that connects the working chamber of the plunger to the intermediate chamber through the magnetic core, and an outlet side of the communication path and the flow path. A diaphragm was provided on each outlet side.

[Actions and effects of the invention]

In the hydraulic control valve device according to the present invention, the electromagnetic pyro 7
) In a valve, there is a pressing force due to hydraulic pressure acting on one side of the valve body, and a driving force from the plunger acting on the other side (back) of the valve body through the mouth and door (corresponding to the current value applied to the electromagnetic coil). The axial movement position of the valve body is determined by the can, which determines the flow rate flowing from the pilot chamber to the low pressure chamber, and the pilot pressure corresponding to the flow value to the electromagnetic coil is obtained. A portion flows from one side of the valve body through the outer periphery of the valve body and rod into the working chamber of the plunger, flows from the working chamber through the connecting path to the intermediate chamber, and from the intermediate chamber flows through the flow path to the low pressure chamber. The air mixed in the working fluid in the working chamber during the plunge is automatically discharged in the form of bubbles toward the low pressure chamber by the flowing working fluid as described above.Therefore, the air in the working chamber of the plunger is The problem caused by the retention of air, that is, the problem caused by the spring action of air acting on the plunger, is prevented, and the pilot pressure corresponding to the current value applied to the electromagnetic coil can be stably obtained. In a valve device, when the pilot pressure is controlled to be reduced by an electromagnetic pilot valve and the load path of the pressure control valve is connected to the discharge path, the liquid discharged from the load path to the discharge path flows out of the electromagnetic pilot valve. Even if there is interference with the liquid discharged through the passage, the pressure fluctuation due to the interference will be transmitted directly to the low pressure chamber, but the transmission to the valve body and plunger will be suppressed by each calibration. The vibration of the plunger body and plunger is suppressed to prevent the occurrence of abnormal noise, and the electromagnetic pilot valve accurately reduces the pilot pressure (strictly speaking, the pressure is discharged from the load path to the discharge path). Although the flow of the hydraulic fluid discharged through the outflow channel is momentarily inhibited by the hydraulic fluid that has been discharged, the vibrations of the valve body, rod, and plunger in the electromagnetic pilot valve are suppressed, and these can quickly perform the intended operation. conduct,
As a result, the pressure reduction control is performed accurately), and the responsiveness of the pressure control valve is improved compared to the conventional method. In addition, the diameter of the restriction installed in the passage connecting the pilot chamber to the low-pressure chamber is set so as not to interfere with flow control, and the diameter of the restriction installed in the passage connecting the intermediate chamber to the low-pressure chamber is set to ensure air discharge. Since it can be set so that there is no problem with the flow rate controllability and air discharge performance, it is possible to suppress the pressure fluctuations caused by the above-mentioned interference from being transmitted to the valve body, rod, and inside the plunger. can.

【Example】

Figure 1 shows the absorbers RrRH, RrLH, and
This figure shows a control valve unit circuit for supplying control hydraulic pressure to the FrRH and FrLH (these are well-known valves installed on each of the four wheels, front, rear, left, and right, and details are omitted from the illustration). Pressure oil discharged from the driven hydraulic pump 10 is guided to a supply path 12 through a filter 11 and stored in a cow humerator 13, and is controlled to a predetermined pressure (line pressure) by a bypass valve 14. ing. In addition, supply route 1
The pressure of No. 2 is detected by a pressure sensor 15. The bypass valve 14 is composed of a main valve 14a, an electromagnetic pilot valve 14b, and an orifice 14c, and the pilot pressure generated downstream of the orifice 14c by the operation of the electromagnetic pilot valve 14b is guided to the main valve 14a to relieve the main valve 14a. The operation is controlled. Note that the hydraulic oil relieved through the bypass valve 14 flows into the reservoir 17 through the discharge path 16. Therefore, the line pressure of the supply path 12 is controlled by each valve unit consisting of a cut valve 20, a pressure control valve 30, and an electromagnetic pilot valve 40, and is applied to each absorber Rr RH, Rr L H, FrRH, FrLH, respectively. It is meant to be guided. Each cut valve 20 operates when the line pressure is less than a predetermined low pressure.
The load path 18 connected to each absorber is cut off to prevent pressure release from each absorber, and when the line pressure is higher than a predetermined low pressure, the load path 18 is opened to communication. This automatically prevents abnormal decreases in the absorber supply pressure. Note that the hydraulic oil leaking from each cut valve 20 returns to the reservoir 17 through the drain passage 21. In addition, the manual on-off valve indicated by the symbol V in the figure is
This is for returning pressure oil to the reservoir 17 through the discharge path 16 during inspection. Each pressure control valve 30 is a pilot-type pressure control valve that controls the pressure of each load path 18 according to the pilot pressure supplied through the pilot path 19, and is connected to the supply boat connected to the supply path 12 and the discharge path 16. and an output port connected to each load path 18,
It operates in response to feedback pressure led from the load path 18 and pilot pressure led through the pilot path 19 from upstream of the electromagnetic pilot valve 40. In this pressure control valve 30, when the pilot pressure is equal to the feedback pressure, the communication between the load path 18, the supply path 12, and the discharge path 16 is cut off as shown in the figure to maintain the pressure in the load path 18, and the pilot pressure is Higher than feedback pressure (
When the pilot pressure becomes lower than the feedback pressure, the load path 18 is connected to the discharge path 16 to increase the pressure in the load path 18. lower. The solenoid pilot valve 40 includes a sleeve 41. as shown in enlarged detail in FIG. It is composed of a valve section consisting of an orifice 42 and a needle valve body 43, and a solenoid device 44 that controls the axial movement of the needle valve body 43.
The body 45 has an inflow passage 45a connected to the supply passage 12 and an outflow passage 45b connected to the discharge passage 16. It is formed. The sleeve 41 is screwed onto the magnetic core 44a of the solenoid device 44 together with the shim plate 46, and has a valve hole 418 in the center. Further, an orifice 42 is fitted and fixed to the left end of the sleeve 41 in the drawing, and the valve hole 41
a pilot room R communicating with the pilot path 19 between
O is formed. The needle valve body 43 has a valve hole 41a provided in the sleeve 41.
The flow rate of the hydraulic oil flowing into the low pressure chamber R1 (communicated with the outflow passage 45t+) through the throttle 01 is controlled by axial movement, and the pilot chamber RO is controlled in cooperation with the orifice 42.
A pair of land portions 43a, 43b (notches 43 a 1. 43 on the outer periphery)
The rod 44b of the solenoid device 44 is slidably assembled in the sleeve 41 in the axial direction at the valve hole 41a, and is pushed to the right in the figure by the hydraulic oil flowing through the valve hole 41a. It is pushed from the back to the left in the figure. In addition, the needle valve body 4
An intermediate chamber R2 is formed on the back of 3.
2 communicates with the low pressure chamber R1 through a communication hole 41b provided in the sleeve 41 and an orifice o2. The solenoid device 44 includes the above-described magnetic core 44a, a rod 44b fitted to the magnetic core 44a so as to be slidable in the axial direction, and a plunger 44c fitted and fixed to the outer periphery of the right end of the rod 44b.
, an electromagnetic filter 44d fitted and fixed to the outer periphery of the magnetic core 44a, a flange 44e assembled to the magnetic core 44a so as to surround the electromagnetic coil 44d, a cylindrical nose 44f, a yoke 44g, etc. It is made up of. A non-magnetic sleeve 44h is attached to the yoke 44g, and a bleeder plug 44I for discharging internal air during assembly is also attached. Further, a cover 44j is provided at the right end of the housing 44f.
is assembled, nousing 44f and cover 44
J is filled with resin 44k. In this solenoid device [44, the electromagnetic coil 44
When energization is applied to d, the magnetic core 448-flange 4
A loop-shaped magnetic path is formed by the 4e-housing 44f-yoke 44g and the plunger 44c, and an electromagnetic force proportional to the current value applied to the electromagnetic coil 44d is applied to the needle valve body 43 through the plunger 44c and the opening/metal 44b. It is now granted to Further, in this embodiment, a groove 44b1 extending to both ends is formed on the outer periphery of the rod 44b, and an axial through hole 44g is formed in the magnetic core 44m and the plunger 44c.
1. 44 cl is formed, and the plunger 4
The working chamber R3 of the needle valve body 4c communicates with an intermediate chamber R2 formed at the back of the needle valve body 43. In this embodiment configured as described above, in the electromagnetic pyrotechnic valve 40, a pressing force is applied by the hydraulic pressure acting on the left side of the needle valve body 43, and a pressing force from the plunger 44C acting on the right side (back) via the rod 44b. The axial movement position of the needle valve body 43 is defined by the driving force (force corresponding to the current value applied to the electromagnetic coil 44d), the flow rate flowing from the pilot chamber Ro to the low pressure chamber R1 is defined, and the flow rate to the electromagnetic filter 44d is determined. A pilot pressure corresponding to the applied current value can be obtained. Further, a part of the above-mentioned flow rate flows from the left side of the needle valve body 43 through the notches 43m1, 43bl of the needle valve body and the groove 44b1 of the mouth, and flows into the working chamber R3 of the plunger 44 from the working chamber R3 through the through hole. The plunger 4
The air mixed in the hydraulic oil in the working chamber R3 and intermediate chamber R2 of 4c is automatically discharged in a bubbled state toward the low pressure chamber R1 by the flowing hydraulic oil as described above. Therefore, problems caused by air remaining in the working chamber R3 and intermediate chamber R2 of the plunger 44c, that is, problems caused by the spring action of the air acting on the plunger 44c, are prevented, and the current value applied to the electromagnetic coil 44d is reduced. The corresponding pilot pressure can be stably obtained. Further, in this embodiment, the pilot room R. A passage connecting the intermediate chamber R2 to the low pressure chamber R1 and the intermediate chamber R2 to the low pressure chamber R1.
Restrictions 01 and 02 are provided in the passages connected to the respective passages. Therefore, when the pilot pressure supplied to the pressure control valve 30 is controlled to be reduced by the electromagnetic pilot valve 40 and the load path 18 of the pressure control valve 30 is communicated with the discharge path 16, the load path 18 is connected to the discharge path 16. Even if the hydraulic oil discharged through the electromagnetic pilot valve 40 interferes with the hydraulic oil discharged through the outflow passage 451), the pressure fluctuation due to the interference is directly transmitted to the low pressure chamber R1, but each throttle 01,
02, the transmission to the needle valve body 43, rod 44b, and plunge center 44c is suppressed. Therefore, the needle valve body 4 in the electromagnetic pilot valve 40
3, the vibration (axial movement) of the rod 44b and the plunger 44c is suppressed, and the generation of abnormal noise is prevented.
Since the pressure reduction control of the pilot pressure by the electromagnetic pilot valve 40 is performed accurately (strictly speaking, the flow of the hydraulic oil discharged through the outflow passage 45b is instantaneously caused by the hydraulic oil discharged from the load passage 18 to the discharge passage 16). Although it is hindered,
Needle valve body 43 and rod 4 in electromagnetic pilot valve 40
4b and plunger 44c are suppressed, and they quickly perform their intended operations, resulting in accurate pressure reduction control), the responsiveness of the pressure control valve 30 is improved compared to the conventional one. do. In addition, the diameter of the throttle 01 provided in the passage connecting the pilot chamber Ro to the low pressure chamber R1 is set so as not to interfere with flow control, and the diameter of the throttle 01 provided in the passage connecting the intermediate chamber R2 to the low pressure chamber R1 is set. Since the diameter of the needle valve body 43, rod 44b, and plunger 44c can be set so as not to interfere with air evacuation performance, pressure fluctuations due to the above-mentioned interference can be set to the needle valve body 43, rod 44b, and plunger 44c while ensuring both flow rate controllability and air evacuation performance. transmission can be suppressed. In addition, although the rod 44b and the valve body 43 were shown as separate bodies in the above embodiment, the rod 44b and the valve body 43 may be integrated.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram of a control valve unit of an automotive hydro-dinimatic suspension system in which the present invention is implemented, and Fig. 2 is a detailed enlarged view of the electromagnetic pilot valve for the pressure control valve shown in Fig. 1. FIG. Explanation of symbols 12... Supply path, 16... Discharge path, 18... Load path, 19... Pilot path, 3o... Pilot type pressure control valve, 40... Solenoid/Ironoto valve,
418... Valve hole (communication path), 41b... Communication hole (flow path), 42... Orifice, 43... Needle valve body, 44... Solenoid device, 44a... Magnetic core , 44b...rod, 44c...plunger, 4
4d... Electromagnetic coil, 458... Inflow path, 45b.
...Outflow path, RO...Pilot chamber, R1...Low pressure chamber, R2...Intermediate chamber, R3...Plunger working chamber, 01,02...Aperture.

Claims (1)

[Claims] A pilot type pressure system that is equipped with a supply path, a load path, a discharge path, and a pilot path, and controls the communication between the load path, the supply path, and the discharge path according to the pilot pressure supplied through the pilot path to control the pressure in the load path. A control valve, an electromagnetic pilot valve that includes an inlet passage connected to the supply passage and provided with an orifice, and an outflow passage connected to the discharge passage, and controls the pilot pressure applied to the pilot passage. In the hydraulic control valve device, the electromagnetic pilot valve has a pilot chamber formed downstream of the orifice and communicating with the pilot passage, and a liquid flowing from the pilot chamber through a communication passage to a low pressure chamber communicating with the outflow passage. A valve body that controls the flow rate by axial movement and forms an intermediate chamber that communicates with the low pressure chamber through a flow passage at the back, a rod that pushes the valve body in the axial direction from the back, and a rod operating hole that the rod passes through. a magnetic core having a central portion thereof, a plunger that faces an end surface of the magnetic core and drives the valve body in the axial direction via the rod, an electromagnetic coil that applies an attractive magnetic field between the magnetic core and the plunger, and and a solenoid device including a connection path that connects the working chamber of the plunger to the intermediate chamber through the magnetic core, and throttles are provided on the exit side of the communication path and the exit side of the flow path, respectively. A hydraulic control valve device characterized by: