JPH0515668Y2 - - Google Patents

Description

[Detailed explanation of the idea] (b) Industrial application fields The present invention relates to a pressure regulating valve.

(b) Conventional technology For example, as a conventional pressure regulating valve,
There is one shown in No. 226708. In this pressure regulating valve, a spool having a plurality of lands with different diameters is fitted into the valve hole of the valve body so as to be movable in the axial direction. The structure is such that lands smaller in diameter than this are arranged on both sides of this. In a valve hole that accommodates such a spool, it is necessary to provide a hole with a large inner diameter that corresponds to a large-diameter land at a position deeper than a hole with a small inner diameter that corresponds to a small-diameter land, but such machining is generally not possible. Have difficulty. For this reason, by fitting a sleeve into a part of the valve hole that requires a small inner diameter,
A small inner diameter corresponding to a small diameter land is obtained. When such a sleeve is used, the concentricity between the hole formed by the inner diameter of the sleeve and the hole machined in the valve body is lower than that of a normal single valve hole. This is due to looseness in the fitting between the outer diameter of the sleeve and the hole in the valve body.
This is also caused by an error in concentricity between the outer diameter and inner diameter of the sleeve. For this reason, the above patent application
In No. 226708, the spool is divided into two parts, and the part that fits directly into the hole in the valve body and the part that fits into the sleeve are separated to prevent concentricity from interfering with smooth operation of the spool.

(c) Problems to be solved by the invention However, in the case of such a pressure regulating valve in which the spool is divided into two, there is a problem in that vibrations in the regulating hydraulic pressure are likely to occur. In other words, when oil is discharged for pressure regulation through the outer periphery of the contact area of the spools, if the flow rate becomes large and a strong jet hits the contact area of the spools, the two spools may separate, albeit slightly. However, for example, the smaller spool is more likely to vibrate. This causes hydraulic vibrations,
It becomes impossible to obtain the desired pressure regulating effect. The present invention aims to solve these problems.

(d) Means for solving the problem The present invention solves the above problem by preventing the influence of the flow of oil for pressure regulation from reaching the contact ends of the two spools. That is, in the pressure regulating valve according to the present invention, a land 32a is provided adjacent to the contact end 30a of the first spool 30 to block the influence of the oil flow for pressure regulation on the contact end side. The oil chamber 52 formed between the land of the first spool and the second spool 31 is always in communication with the drain port 26b. Note that the reference numerals in parentheses indicate corresponding members in the embodiments described later.

(e) Action When the pressure regulating valve performs the pressure regulating action, oil flows from a predetermined port of the first spool to another port, but the jet of oil hits the land on the contact end side of the first spool. Therefore, the contact end is not affected. The oil chamber formed between the land of the first spool and the second spool is connected to the drain port, so a small amount of oil that has flowed in through the small gap between the land and the valve hole is drained into the drain port. Exhausted from the port. Therefore, since the two spools are not separated by the flow of oil, a predetermined pressure regulating action can be obtained without generating hydraulic vibration.

(F) Embodiment FIG. 1 shows a pressure regulating valve 10 which is an embodiment of the present invention.
shows. The pressure regulating valve 10 includes a valve hole 20 formed in a valve body 11, a first spool 30 fitted into the valve hole 20 and movable in the axial direction, and a sleeve 2 fixed to the valve hole 20 with a pin 24.
2, and a second spool 31 fitted to the inner diameter portion of the sleeve 22 so as to be movable in the axial direction. The first spool 30 has lands 32a, 32
b, 32c and 32d. Land 32
a, 32b and 32c have the same diameter, and land 3
2d has a smaller diameter than these. Further, the first spool 30 has a contact end 30a that contacts the second spool 31 at the right end in the figure. The second spool 31 has a land 33 that fits into the inner diameter of the sleeve 22. In addition, in land 33,
A groove 33a in the circumferential direction is provided to prevent dirt from getting caught between the inner diameter portion of the sleeve 22 and the sleeve 22. The groove 33a is arranged so as to be located at the entrance of the inner diameter part of the sleeve 22 during pressure regulation. In addition,
Similar grooves 33b are provided in symmetrical positions in the land 33, and this is because the second spool 31 has a symmetrical shape in the axial direction so that it can be assembled in any direction. The second spool 31 has a contact end 31a at the left end in the figure. 1st
Springs 36a and 36b are provided on the left side of the spool 30 in the figure. Ends of the springs 36a and 36b opposite to the side that contacts the first spool 30 are supported by a support member 34 that is movable in the axial direction. The support member 34 is provided movably in the axial direction within a sleeve 62 that is press-fitted into one end of the valve hole 20 of the valve body 11 . A lever 64 that moves in accordance with, for example, the gear ratio is in contact with the end of the cap-shaped support member 34 on the opposite side from the spring arrangement side. Since the lever 64 is disposed within the axial notch 62a provided in the sleeve 62 (the notch 62a
has a width dimension that allows the passage of the lever 64),
The support member 34 can be pushed into the sleeve 62 and moved further to the right in FIG. By providing the sleeve 62 in this way, the support member 34 can be removed without increasing the size of the valve body 11.
Sufficient support length can be ensured. Note that the support member 34 has a groove 34a on the outer periphery, and an oil passage 60 and a sleeve 6 are connected to this groove 34a.
Hydraulic pressure for lubrication is supplied from hole 63 of No. 2,
This reduces the frictional resistance of the support member 34.

The valve hole 20 has ports 26a, 26b, 26c, 2
6d, 26e, 26f, 26g and 26h. The ports 26a, 26d, and 26e communicate with the discharge side of the oil pump 42 via an oil passage 40. The oil pump 42 sucks the oil in the oil tank 44 through the strainer 46 to the oil passage 40.
Discharge to. The port 26f is a drain port, and oil discharged from this port is supplied to another valve (not shown) via an oil passage 48. The port 26g communicates with a throttle valve (not shown) via an oil passage 49. In addition, port 26b,
Port 26c and port 26h are drain ports and communicate with oil tank 44 via oil passage 50. Sleeve 22 has a hole 22a that communicates port 26a with the inner diameter.

Next, the operation of this embodiment will be explained. When oil is discharged from the oil tank 44 to the oil passage 40 by the oil pump 42, the oil pressure in the oil passage 40 is increased to the port 26a.
It acts as a pilot pressure on the land 33 of the second spool 31 through the hole 22a, pushes the second spool 31 to the left in the figure, and simultaneously pushes the contact end 31a.
and by pushing the first spool 30 connected via the contact end 30a to the left in the figure and discharging the oil from the port 26d to the port 26c, and by discharging the oil from the port 26e to the port 26f. , the first spool 30 and the second spool 3
1 is in a pressure regulating state as shown in the figure. As a result, the oil pressure in the oil passage 40 is regulated to a value corresponding to the force of the springs 36a and 36b and the force due to the throttle pressure acting from the oil passage 49 on the port 26g.
During this pressure adjustment, oil is discharged from the port 26d to the port 26c as described above, but the port 26c is separated from the oil chamber 52 where the contact end 30a and the contact end 31a are located by the land 32a. Because it is isolated, a large amount of oil becomes a jet and flows into port 2.
6c, the contact end 30a and the contact end 31a are not affected at all. Therefore, the contact end 30a and the contact end 31a do not separate, and no hydraulic vibration occurs. In addition, the land 32a
Some oil leaks into the oil chamber 52 through a small gap between the outer periphery of the valve hole 20 and a small gap between the land 33 of the second spool 31 and the inner diameter of the sleeve 22. Since it is discharged from 26b, it does not affect the pressure regulating action.

(g) Effects of the invention As explained above, according to the invention, 2
A land was provided between the mutually contacting ends of the two spools and the oil flow for pressure regulation.
Since the contact ends of the two spools do not separate, hydraulic vibration can be prevented, and pressure regulation accuracy can be improved.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a pressure regulating valve according to an embodiment of the present invention. 20...Valve hole, 26b...Drain port, 3
0...First spool, 31...Second spool, 3
0a...Contact end, 31a...Contact end, 32a
...Rand, 52...Oil room.

Claims (1)

[Claims for Utility Model Registration] A first spool and a second spool are fitted in series in one valve hole, and the first spool and the second spool are in contact with each other at their respective contact ends facing each other in the axial direction. The first spool is movable, and the first spool is adjacent to the contact end of the first spool in a pressure regulating valve that controls oil discharge for pressure regulation according to the force of pilot pressure acting on the second spool. A land is provided to block the influence of the oil flow for pressure regulation on the contact end side, and the oil chamber formed between the land of the first spool and the second spool is always connected to the drain port. A pressure regulating valve characterized by being in communication.