JPH0571566U - Solenoid pressure control valve - Google Patents

Abstract

(57) [Summary] [Purpose] An object is to realize an electromagnetic pressure control valve that can control a spool quickly and accurately and can stably drive a load. [Structure] An electromagnetic pressure control valve is provided in which a flow rate suppressing unit for suppressing an excessive flow rate of a fluid is provided on a land of a spool. Also, an electromagnetic pressure control valve having a flow rate suppressing means constituted by a step portion and an inclined surface is constituted.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an electromagnetic pressure control valve, and more specifically, an exciting current is applied to the solenoids of the operating parts on both sides of the body to cause the spool to slide and the ports formed on the body by the lands of the spool to alternate. It relates to an electromagnetic pressure control valve that drives the load by switching to.

[0002]

[Prior Art]

 FIG. 5 shows an electromagnetic pressure control valve of this type, which is exemplified by the device described in JP-A-47-22516.

In FIG. 5, 1 is a spool, and 2 to 5 are lands having a rectangular cross section. 6 is a housing, 7 is a spool chamber, 8-10 are wheel grooves, 11 is a communication passage, 12 and 13 are spring chambers, 14 is a spring seat, 15 and 16 are centering springs, and 17 and 18 are feedback fluid paths. is there. Spring seats 14 and 14 and centering springs 15 and 16 are housed inside the left and right spring chambers 12 and 13, respectively. 21 is a cap, 22 is a gap, 23 is a solenoid, 24 is a fixed iron core, 25 is a movable iron core, 25a is a push rod, 27 is a coil, and 28 is a bearing. A and B are cylinder ports, P is a pump port leading to a pressure source, T is a return port, 30 is a driven element, and 31 and 32 are fluid circuits.

In the conventional device having such a configuration, when the solenoid 23 on the right side is excited, the spool 1 is displaced leftward from the neutral position in the drawing via the push rod 25a. When the spool 1 is displaced to the left, the pump port P and the cylinder port A communicate with each other and the cylinder port B communicates with the return port T. Then, the fluid of the pressure source flows through the circuit 31 and drives the driven element 30, for example, in the forward direction. The fluid flowing into the cylinder port A is guided from the feedback fluid passage 17 to the left spring chamber 12 and pushes back the spool 1 which is displaced to the left. These two opposite forces balance to stop the spool 1 in place.

On the other hand, a part of the fluid flowing into the spring chamber 13 flows into the cap 21 through the gap 22. The fluid in the cap 21 can eliminate the sliding friction resistance of the push rod 25a for pushing the spool 1 and the displacement amount of the spool 1 can be made exactly proportional to the acting force of the solenoid 23. Similarly, by exciting a solenoid on the left side (not shown), the pump port P is switched to the cylinder port B, fluid pressure is introduced into the circuit 32, and the driven element 30 is driven in the opposite direction. ing.

[0006]

[Problems to be solved by the device]

 As described above, in the conventional electromagnetic pressure control valve, the lands 2 and 3 of rectangular cross section provided on the outer periphery of the spool 1 are displaced to connect the pump port P to the cylinder ports A and B. Then, the pressurized fluid from the pump port P is fed back to the spring chambers 12 and 13, and is further introduced into the cap 21 through the gap 22. Therefore, when the lands 2 and 3 having a rectangular cross section open the cylinder ports A and B, the flow passage may open greatly, and an excessive amount of pressurized fluid may momentarily flow from the pump port P. For this reason, a flow hose of strong pressurized fluid is added to the spool 1, and it takes time for the spool 1 to vibrate and equilibrate. If the equilibrium time becomes longer due to the vibration of the spool 1, there is a problem that the driving of the driven element 30 eventually becomes unstable.

The present invention has been made in order to solve such a problem of the conventional device, and is provided with features such as suppressing excessive inflow of the fluid to be pressurized and being driven in a stable operation. The purpose is to realize an electromagnetic pressure control valve.

[0008]

[Means for Solving the Problems]

 This invention is provided with a spool that opens and closes ports by abutting both ends of rod members driven by operating parts provided on both sides of the body to change the position relative to the body and switching the ports. In the electromagnetic pressure control valve that controls the spool to the position corresponding to the input current of the solenoid of the operation part by returning the output fluid discharged from the port by the flow rate control means that suppresses the excessive flow rate of the fluid to the land of the spool. The electromagnetic pressure control valve is provided with.

Further, the electromagnetic pressure control valve is constituted by a step portion provided at the end portion of the land in the spool as the flow rate suppressing means.

Further, the electromagnetic pressure control valve is constituted by the flow rate suppressing means having an inclined surface provided at the end of the land in the spool.

[0011]

[Action]

 When the solenoid on the right operation part is excited, the spool slides in the sliding hole of the sleeve and is displaced to the left. The displacement of the spool in the left direction causes the pair of lands to connect the pump port to the left port and the right port to the tank port. The pressurized fluid of the pump port that has flowed into the left-side load port flows into the load line and drives the load in the positive direction. At the same time, part of the pressurized fluid that has flowed into the left port is introduced into the feedback chamber to balance the spool. Also, the fluid in the right-hand load port flows from the oil groove to the right-hand operation part to lubricate the bearings and the like.

[0012] Similarly, the left solenoid balances the spool to the right balance position, and the load is driven in the opposite direction by the pressurized fluid that has flowed in while being restrained by the right port. The interior is lubricated. The pressurized fluid of the pump ports flowing into the left and right rod ports receives a flow resistance by the wide flow rate control means formed in the land to suppress excessive inflow and drive the load stably.

[0013]

Embodiment 1 FIG. 1 is a structural explanatory view of an embodiment of the present invention, and FIG. 2 is a perspective view of the sleeve of FIG. In the drawings of the embodiments of the present invention, the same parts as those of the conventional device may be slightly different in structure and function. Therefore, different reference numerals are given, and a part of the description will be repeated but will be described in some detail. Also, in FIG. 1, the left and right sides of the center line XX are symmetrically formed as in the conventional drawing, so that the illustration of the left side portion is omitted.

In FIG. 1, reference numeral 1 is a main body of the pressure control valve. 2 is a body of the main body 1 and 20 is a body hole. The body hole 20 is provided in the axial direction of the body 2. Reference numeral 21 is a pump port, 22 is a pair of left and right load ports of the pump port 21, 23 is a pair of outer tank ports, and each of the ports 21 to 23 is an annular ring provided on the inner peripheral surface of the body hole 2. It is composed of grooves. Reference numeral 24 is a communication passage provided in the body 2 for connecting the left and right tank ports 23 to each other. Although not shown, each port 21 to 23 of the pressure control valve shown in FIG. 1 also has a load (= driven element) such as a pressure source of a pump or a fluid motor and a tank, like the conventional device of FIG. A fluid circuit is composed of a tank and the like connected to a port (return port).

Reference numeral 3 is a sleeve, and 4 is a symmetrical spool. The structure of the sleeve 3 is shown in FIG. Reference numeral 30 is a sliding hole provided in the shaft center, 31 to 33 are port holes, 34 is a flange, 35 is an oil groove portion, and 36 is a thin wall portion. The port holes 31 to 33 are provided so as to extend in the radial direction of the sleeve 3 and correspond to the ports 21 to 23 of the body 2 by single digit numbers. Further, the oil groove portion 35 and the thin portion 36 correspond to the gap 22 of the above-mentioned conventional device, and form a flow passage connecting the inside of the operation portion described later and the left and right tank ports 23. Then, the sleeve 3 is fixed to the body hole 20, for example, by interference fitting, leaving the flange 34.

A pair of wide lands 42 in FIG. 1 is formed in the middle of the spool 4. 43 is a pair of lands having a narrow width on the outside thereof, 44 is a small diameter portion at both left and right ends, 45 is a land hole provided in the diameter direction of both lands 42 having a wide width, and a dotted line 46 is an internal flow path. An enlarged view around the wide land 42 on the left side is shown in FIG. The wide land 42 is formed in a concave shape having a groove on the outer periphery, a land hole 45 is opened in the groove, and step portions 47 for suppressing the flow rate are formed at both ends.

Reference numeral 5 denotes an operation unit. Reference numeral 51 is a dry coil of the solenoid of the operating section 5, 52 is a wet armature type fixed iron core, 53 is a movable iron core, 54 and 55 are bearings, 56 is a rod member, and 57 is a stopper. A short shaft-shaped push rod 58 at the tip of the rod member 56 is made to have almost the same diameter as the spool 4, and a long shaft-shaped rod 59 to which a movable iron core 53 is fixed is axially reciprocated in a thrust type bearing 55. It is movably supported. The push rod 58 is inserted into the sliding hole 30, and the tip end thereof is in contact with both end surfaces of the spool 4. The left and right abutting portions of the rod member 56 and the spool 4 communicate with the land hole 45 via the internal flow path 46 indicated by the broken line of the spool 4. A narrow gap is formed between the left and right abutting portions by the small diameter portion 44, and the feedback chambers Rl and Rr are formed by this gap.

The operation of the pressure control valve of the present invention having the above structure will be described below. When the solenoid coil 51 of the operation unit 5 on the right side is excited by the input current, the fixed iron core 52 is magnetized and the spool 4 is pushed by the push rod 58 and displaced leftward. Then, the pump port 21 communicates with the left load port 22 through the port hole 31 of the sleeve 3, and at the same time, the right load port 22 also communicates with the right tank port 23 through the port hole of the sleeve 3.

Therefore, the flow path in the right load port 22 connected to the tank port 23 is opened, and the pressurized fluid of the pressure source is discharged to the load line via the pump port 21 and the left load port 22. To be done. A part of the pressurized fluid in the left port 22 is introduced into the feedback chamber Rl through the land hole 45 of the spool 4 and the internal flow path 46. The spool 4 is pushed back to the right by the feedback pressure guided to the feedback chamber Rl, and the spool 4 is equilibrium stopped at a position where two forces, that is, rightward and leftward, are balanced. The pressurized fluid flowing into the load line applies a driving force corresponding to the input current of the solenoid coil 51 to the load to drive the load in the forward direction, for example. Further, the fluid in the right tank port 23 permeates the inside of the operation portion 5 through the oil groove portion 35 to lubricate the wet armature type fixed iron core 52, the bearing 55 and the like.

Similarly, the spool 4 is slid in the sliding hole 30 of the sleeve 3 in the right direction by the solenoid coil 51 on the left side (not shown) to equilibrate it to the balance position on the right side. The pressurized fluid that has flowed in from the right-side load port 22 drives the load in the opposite direction, and the inside of the left-side operation portion 5 is lubricated by the fluid in the tank port 23 that has flowed through the gap of the thin portion 36. The pressurized fluid of the pump port 21 that flows into the left and right rod ports 22 is provided at the inlet and has a wide flow resistance at the step portion 47 of the land 42, and an excessive inflow is suppressed to stably drive the load.

Embodiment 2 FIG. 4 is an explanatory view of another embodiment of the present invention. In the second embodiment, instead of the stepped portion 47 of the first embodiment described above, inclined surfaces 48 for suppressing the flow rate are provided at both ends of the land 42. Then, as shown in the drawing, a rough surface 49 having a linear shape or a crossing linear shape is formed on the surface of the inclined surface 48.

Also in the second embodiment having such a configuration, similarly to the first embodiment, the spool 4 slides in the sliding hole 30 of the sleeve 3 by the electromagnetic force so that the load port 22 communicates with the pump port 21. It At this time, the land 42 momentarily opens the pump port 21, and the pressurized fluid from the pump port 21 starts to rapidly flow into the load port 22. However, the inflowing pressurized fluid receives viscous resistance due to the inclined surface 48 provided at the inlet of the rod port 22 and forming the rough surface 49. As a result, the inclined surface 48 fulfills exactly the same function as the stepped portion 47 of the first embodiment, and the excessive inflow of the pressurized fluid is suppressed, and the load can be operated stably.

In the above-described embodiment, the case where the sleeve with the flange having the oil groove portion and the thin portion at both ends is fixed to the body hole and the spool and the push rod are fitted is described. The body hole may constitute a sliding hole, and the spool and the rod member may be directly fitted into the sliding hole. Further, although the rod member having two parts, that is, the short-axis push rod and the long-axis rod has been illustrated and described, an integral rod member may be configured. Furthermore, although a rotary type motor whose load is driven by a fluid has been described, the present invention may be applied to a linearly driven piston.

[0024]

[Effect of the device]

 The present invention is provided with a spool for opening and closing a port by abutting both ends of a rod member driven by an operating portion provided on both sides of the body to change a position relative to the body and switching the port. In the electromagnetic pressure control valve that controls the spool to the position corresponding to the input current of the solenoid of the operation part by returning the output fluid discharged from the port due to the displacement of, the excessive flow rate of the fluid to the land of the spool is suppressed. An electromagnetic pressure control valve with a flow control means was constructed.

In addition, the electromagnetic pressure control valve is configured in which the flow rate suppressing means is configured by the step portion provided at the end portion of the land in the spool. Furthermore, an electromagnetic pressure control valve is constructed in which the flow rate suppressing means is composed of an inclined surface provided at the end of the land on the spool.

Therefore, the pressurized fluid of the pump ports flowing into the left and right rod ports is subjected to flow resistance by the flow rate suppressing means constituted by the stepped portion provided on the land of the inlet, the rough surface, etc., and the excessive inflow is suppressed. Will be. As a result, the spool in the sliding hole moves quickly and smoothly without vibration and balances, so that the driving operation of the load is extremely stable.

Therefore, according to the present invention, it is possible to provide an electromagnetic pressure control valve having features such as stable spool control.

[Brief description of drawings]

FIG. 1 is a structural explanatory view of an embodiment of the present invention.

2 is a perspective view of the sleeve of FIG. 1. FIG.

FIG. 3 is an enlarged explanatory diagram of a main part of the first embodiment of the present invention.

FIG. 4 is an enlarged explanatory view of a main part of the second embodiment of the present invention.

FIG. 5 is an explanatory diagram of a configuration of a conventional device.

[Explanation of symbols]

 2 body 3 sleeve 4 spool 5 operation part 20 body hole 21 pump port 22 rod port 23 tank port 30 sliding hole 31 to 33 port hole 42 wide land 43 narrow land 45 land hole 47 step 48 slanted surface 49 rough surface 51 Solenoid Coil 52 Fixed Iron Core 53 Movable Iron Core 56 Rod Member 58 Push Rod Rl and Rr Feedback Chamber

Claims (3)

[Scope of utility model registration request] 1. A spool which opens and closes a port by opening and closing a port by abutting both ends of a rod member driven by an operating portion provided on both sides of the body to change a position relative to the body, In an electromagnetic pressure control valve that controls the spool to a position corresponding to the input current of the solenoid of the operation unit by returning the output fluid discharged from the port due to displacement, suppressing an excessive flow rate of the fluid on the land of the spool An electromagnetic pressure control valve, characterized in that it is provided with a flow rate suppressing means. 2. The electromagnetic pressure control valve according to claim 1, wherein the flow rate suppressing means is constituted by a step portion provided at an end portion of a land in the spool. 3. The electromagnetic pressure control valve according to claim 1, wherein the flow rate suppressing means is constituted by an inclined surface provided at an end portion of a land in the spool.