JPH02129478A - Pressure regulating valve - Google Patents

Abstract

PURPOSE:To reduce a friction factor and increase abrasion resistance as well as to make improvements in fatigue resistance by applying soft nitriding to the surface of a push rod of an electromagnet part making load by an electromagnet act on a spool valve. CONSTITUTION:Load by an electromagnet part 3, energizing force of a spring 6 and output pressure feedback load all are made to act on a spool valve 5 sliding in a valve sleeve 4 with those of supply port 21, output port 22 and exhaust port 23, and thereby output pressure is regulated by the balance. Soft nitriding 38a is applied to the surface of push rod 38 of the electromagnet part 3 making the load act on the spool valve 5, and a friction factor to a ball 91 being held by a bearing cage 83 is reduced, thereby enhancing the extent of abrasion resistance. Thus, improvement in fatigue resistance is contrived.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a pressure regulating valve, and more particularly to an electromagnetic pressure regulating valve that controls fluid pressure in response to an electrical signal.

(Prior Art) Conventionally, typical electromagnetic pressure regulating valves include a diaphragm type that receives feedback pressure on a diaphragm surface and a spool type that receives feedback pressure on a spool end surface. relates to the latter spool type electromagnetic pressure regulating valve.

Such a conventional spool-type electromagnetic pressure regulating valve applies a load from an electromagnet, a spring load, and an output pressure feedback load to a spool valve that slides inside a valve sleeve that has a supply port, an output port, and a discharge port. By balancing the loads, the supply pressure is adjusted to an output pressure corresponding to the electric signal input to the electromagnet section, and the output pressure is output (see Japanese Utility Model Application Publication No. 60-52509).

Here, since the push rod that transmits the load generated by the electromagnet in the pressure regulating valve has an excitation coil on the outer periphery of the rod, it is desirable to be made of a non-magnetic material in order to reduce leakage magnetic flux.

For this purpose, stainless steel is used, for example.

However, when such a non-magnetic material is used for the push rod, wear resistance becomes a problem.

For this reason, conventionally, as shown in FIG. 5, a plunger member 202 is attached to the tip of a push rod 201 made of a non-magnetic material, and a stopper member 203 and a thin sleeve 204 made of iron are inserted into the plunger member 202. Was.

(Problems to be Solved by the Invention) However, in the above conventional pressure regulating valve, even if the thin sleeve 204 made of iron is provided on the pushpiece 201 made of a non-magnetic material, since iron is a ferromagnetic material, Since leakage magnetic flux cannot be eliminated, there is a problem in that the attractive force of the electromagnet decreases.

Furthermore, it is necessary to insert a thin sleeve 204 made of iron into the push rod 201, which inevitably results in a complicated structure.

The present invention provides a pressure regulating valve with a simplified structure that eliminates the problems of the conventional pressure regulating valve, reduces the coefficient of friction, increases wear resistance, and also improves fatigue resistance. The purpose is to

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a supply boat (
21), a spool valve (5) sliding within a valve sleeve (4) having an output port (22) and a discharge port (23);
By applying the load from the electromagnet, the spring load, and the output pressure feedback load to balance these loads, the supply pressure is adjusted to the output pressure corresponding to the input electric signal to the electromagnet part (3). In the pressure regulating valve (1) configured to output, the spool valve (5)
The surface of the push rod (38) of the electromagnet part (3) on which a load is applied is subjected to nitrocarburizing treatment.

(Operation and Effects of the Invention) According to the present invention, as described above, the push rod (38) that applies a load to the spool valve (5) of the pressure regulating valve is arranged, and the surface of the push rod (38) is soft. By applying the nitriding treatment, it is possible to reduce the friction coefficient, increase wear resistance, and improve fatigue resistance.

Furthermore, the structure can be simplified compared to the conventional one.

In addition, in the above description, for convenience of explanation, the first
Although the reference numerals used in the figures and FIG. 2 are given, these do not limit the structure of the present invention.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view of a pressure regulating valve showing a first embodiment of the present invention, and FIG. 2 is a partially cutaway side view of a push rod of the pressure regulating valve.

In FIG. 1, a pressure regulating valve 1 is composed of a pressure regulating valve section 2 and an electromagnet section 3. The pressure regulating valve section 2 is composed of a valve sleeve 4 and a spool valve 5,
The valve sleeve 4 has a large-diameter hole 7 accommodating a spring 6 in its internal axial direction, and a small-diameter guide hole 8 and a medium-diameter guide hole 9 that slide and guide a spool valve 5, which will be described later.
is formed so as to penetrate through it.

On the outer periphery of the valve sleeve 4 corresponding to the guide hole 9, a supply port 21, a discharge port 23, and an output port 22 that are open in the radial direction are formed in order from left to right, and the fluid flow in each of these ports is facilitated. annular notches 21a, 23a as necessary.

34a and 35a are formed.

The spool valve 5 also has two lands 31 and 32 of equal outer diameter which are slidably guided in the guide hole 9 of the medium diameter, and a guide of the small diameter adjacent to one of the land parts 31. The hole 8 is provided with a small diameter land portion 33 that is slidably guided by the liquid. The distance between the opposite ends of the land portions 31 and 32 having the same diameter is such that the output port 22 can communicate with the supply port 21 and the discharge port 23 alternately at a predetermined ratio by sliding the spool valve 5. is formed. Further, the space 34 between the lands 31 and 32 having the same diameter is always connected to the output port 22.

The sealed space 35 formed by the one land portion 31, the small diameter land portion 33, and the guide hole 8.9 is communicated with the space 34 between the land portions 31 and 32 through a feedback oil passage 36. ing.

The feed bank oil passage 36 is formed to diagonally penetrate the land portion 31, and is connected to the output port 22.
The output pressure obtained is fed back and supplied to the sealed space 35.

The rod-shaped portion 37 erected from the center of the end surface of the equal-diameter land portion 32 is a push rod 38 of the electromagnet portion 3, which will be described later.
Also, the portion protruding from the center of the end surface of the small diameter land portion 33 is the contact portion with the guide member 3 of the spring 6.
It is 9.

By the way, a female thread member 51 for applying a load to the spring 6 is formed in the hole 7 of the valve sleeve 4, and a male thread member 52 is formed to be screwed into the female thread member 51.
is installed. Then, by rotating the male screw member 52 and inserting it into the hole 7, the spring 6
can be pressed against the end face of the spool valve 5, and by adjusting the amount of rotation of the male screw member 52, the amount of compression of the spring 6 can be adjusted.

When assembling the pressure regulating valve section 2, the spool valve 5 is first inserted into one end of the valve sleeve 4 in which the hole 8 is formed, with the small-diameter land section 33 facing the hole 7.
The spring 6 is inserted from the side so as to surround the guide member 39 and come into contact with the end surface of the small diameter land portion 33 . Then, while holding the spring 6, the male threaded member 52 is screwed into the female threaded member 51 of the valve sleeve 4, thereby compressing the spring 6 by a predetermined amount.

The pressure regulating valve section 2 assembled in this way is then
A flange portion 5 formed at the end of the valve sleeve 4 on the hole 7 side
3 is opposed to a flange portion 54 of the electromagnet portion 3, which will be described later, and is coupled to the electromagnet portion 3 by caulking an end portion 56 of the case 55. To facilitate the crimping, a step 57 is formed on the inner surface of the case 55 at a portion facing the flange 54, and the crimping is performed with the flange 54 in contact with one part of the step 57. will be held.

Here, the flange portion 53 has a thick portion 61 and a thin portion 6.
2, and a tapered portion 63 is formed on the end surface of the thick portion 61. This tapered portion 63 is for forming a relief when the flange portion 53 is opposed to the flange portion 54 . In other words, because of the relief, the flanges 53 and 54 come into contact only at the peripheral edge 64, so that only the peripheral edge 64 needs to be surface-treated to bring them into contact, making assembly easier. Not only that, but the assembly is also in good condition.

Furthermore, an annular step 65 is formed at the peripheral edge of the thin portion 62 . This annular step 65 corresponds to the pressure regulating valve l after assembly.
It is formed to shorten the length.

In other words, since the pressure regulating valve 1 needs to be as short as possible due to restrictions imposed by its installation location, both flange portions 53
．． 54 is preferably thin. However, there is a limit to how thin the flanges 53 and 54 can be made due to strength issues, so a thick part 61 having a constant thickness is formed, and the other thin part 62 is provided with the annular step. Form 65. With this configuration, this annular step 6
The assembled electromagnet section 3 can be shortened by 5 times.

Note that 6G indicates a supply port 21, a discharge port 23, and an output port 2 provided in the radial direction of the outer circumference of the valve sleeve 4.
This is a notch for positioning between 2 and a hydraulic control system (not shown) of an automatic transmission for an automobile, for example.

After the pressure regulating valve section 2 and the electromagnet section 3 are coupled in this manner, the male threaded member 52 is rotated and moved within the female threaded member 51, and the amount of compression of the spring 6 is adjusted. This adjustment is performed while supplying current to the electromagnet section 3 and monitoring the output pressure of the output port 22. When this adjustment is completed, as shown at 72 in the figure, the protrusion 71 on which the female screw member 51 is formed is caulked from the outside, and the male screw member 52 is fixed. In order to facilitate this caulking, the protruding portion 71 is formed with a thin portion.

Next, the electromagnet section 3 will be explained.

The electromagnet section 3 has a cylindrical case 55 made of a magnetic material, and a thick cylindrical core 81 also made of a magnetic material is accommodated in the case 55.

The core 81 is arranged such that the flange portion 54 formed at one end contacts and engages the flange portion 53 of the valve sleeve 4 . Further, a coil assembly 82 is clamped and fixed at the inner part of the cylindrical space formed by the case 55 and the core 81. The cylindrical case 55, core 81, and coil assembly 82 constitute a stationary portion.

On the other hand, a push rod 38 is inserted into the hollow portion 83 of the core 81, and a plunger 84, also made of a magnetic material, is fixed to the other end of the push rod 38 and is attracted by the coil assembly 82. The movable part is configured by:

In the movable part, the plunger 84 fixed on the other end side of the push rod 38, that is, on the side away from the pressure regulating valve part 2, has a thick disk shape, and its center on the side facing the core 81 A cylindrical recess 84a is formed in the recess 84a, in which the end of the core 81 is accommodated with a minute interval when the plunger 84 is sucked. Further, the outer circumferential portion 84b faces the inner circumferential surface of the case 55 with a similarly small gap therebetween. It looks like this.

A linear 9 rolling bearing 86 is disposed in the hollow portion 83 of the core 81 via a sleeve 85.

After the sleeve 85 is fitted into the hollow portion 83 of the core 81, three circumferential portions of the end face of the core 81 are crimped and deformed, as shown in the figure, to form a stopper 87 to prevent the sleeve 85 from being pulled out.

Further, the linear 9 rolling bearing 86 housed in the sleeve 85 can freely slide within the space within the sleeve 85 while being regulated by stoppers 88 and 89. The linear 9 rolling bearing 86 is housed in a brass bearing cage 90 and a small hole formed so as to pass through the inside and outside of the bearing cage 90.
It consists of balls 91 slightly protruding from the inner and outer peripheries of the rolling bearing 86, and supports the push rod 38 via the balls 91 while allowing relative rotation between the push rod 38 and the sleeve 85.

By the way, the push rod 38 is made of a non-magnetic material such as stainless steel, and its surface is nitrided to form a nitrided layer so as to have wear resistance. and,
At one end thereof, as shown at 92 in the figure, the plunger 8 is attached.
4 is fixed by ring caulking. Further, a tapered portion 93 is formed at the other end of the push rod 38 facing the rod-shaped portion 37 of the spool valve 5 to prevent incorrect assembly.

Note that 94 is a ring made of nonwoven fabric interposed between the end face of the coil assembly 82 and the flange portion 54 of the core 81;
96 is a connector fixed to the outside of the case 55, and 96 is an oil hole formed through the plunger 84 to reduce the resistance of oil filled as a countermeasure against hydraulic vibration at high temperatures. A cover member 97 closes the end of the case 55 on the plunger 84 side.

The electromagnet section 3 is connected to the ring 9 from one end side of the case 55.
4 and the core 81 with the coil assembly 82 fixed thereon,
The flange portion 54 is positioned and fixed using, for example, a step portion 57 formed on one end side of the inner surface of the case 55 to constitute a stationary portion, while a plunger 84 is provided on the other end side of the push rod 38.
After fitting and fixing by ring caulking to form a movable part, a stopper 89 is inserted and one end side of the push rod 38 of the movable part is connected to the case 55 which forms the stationary part.
from the other end of the linear 9 through the sleeve 85.
It is housed in a rolling bearing 86.

Then, the flange portion 53 and the stopper 88 formed on the other end side of the valve sleeve 4 of the pressure regulating valve portion 2 described above are fitted into the case 55 on the one end side of the electromagnet portion 3.
The assembly of the pressure regulating valve 1 is completed by caulking the end portion 56 of the valve sleeve 4 to the outer periphery of the flange portion 53 of the valve sleeve 4.

Since the present embodiment has the above-described configuration, when pressure fluid, such as pressure oil, is supplied from a pump or the like to the supply port 21 of the valve sleeve 4, the pressure oil is supplied from the supply port 21 to the valve sleeve 4 and the spool valve. 50 through the opening formed between the land portions 31 and between the land portions 31 and 32 of the spool valve 5, and further via the output port 22 of the valve sleeve 4 which is always in communication with the land portions 31 and 32. The oil is then supplied to each hydraulic device in a hydraulic system that requires pressure oil, such as an automatic transmission.

The pressure P of the pressure oil output at the output port 22 is simultaneously fed back via the feedback oil passage 36 to the land portion 31 and the small diameter land portion 33 adjacent thereto.
The cross-sectional area A of the land portion 31 is guided into the sealed space 35 formed by the valve sleeve 4.

It is applied to the area difference A + A t obtained by subtracting the cross-sectional area A2 of the small diameter land portion 33 from .

The force (AI A!>P) generated by this pressure is added to the force F3F pressed by the spring 6, and the spool valve 5 is pressed rightward in the figure by (AI Ax )P+Fsp.The spool valve 5 is then The valve sleeve 4 is slid within the valve sleeve 4 to a position where this force and the force F generated by the electromagnet 3 are balanced.

In this way, the sliding displacement of the spool valve 5 moves the land portions 31 and 32, and the supply port 2 of the valve sleeve 4 moves.
1 and the discharge port 23 are controlled to open and close at a predetermined ratio with respect to the output port 22, and as a result, the output pressure P at the output port 22 corresponds to the electromagnetic signal input to the electromagnet part 3, P= (Fs .L Fsp)7 to (A, -A,).

Next, the main structure of the present invention will be explained in detail using FIG. 1 and FIG. 2.

First, apply a load to the spool valve 5 installed inside the valve sleeve 4! The surface of the push rod 38 of the magnet part 3 is subjected to soft nitriding treatment as shown in FIG.

Here, soft nitriding is a method called Tufftriding developed by Degussa of Germany, which is a method of nitriding while blowing air into a KCNO-KC (!-Na, Cow salt bath). Although this treatment does not significantly increase the surface hardness of the object to be treated, it can reduce the friction coefficient, increase wear resistance, and improve fatigue resistance.However, Cr, Mo
, A1. When steel containing V or the like is nitrocarburized, its hardness increases in the same way as normal nitriding.

Here, the push rod 38 is made of stainless steel, and since this stainless steel is an alloy based on Crjg, when soft nitriding is performed, a nitrided layer 38a of 2 to 3 μm is formed as shown in FIG. Can be formed.

With this configuration, the friction coefficient of the push rod 38 can be reduced, the wear resistance can be increased, the fatigue resistance can be improved, and the hardness can also be increased. Therefore, a highly reliable bearing function can be achieved.

In this embodiment, since the ball 91 held in the bearing cage 90 slides on the push rod 38, particularly wear resistance and fatigue resistance are required, so nitrocarburizing is suitable in that sense as well. be.

Furthermore, this push rod 38 needs to be configured so that leakage magnetic flux does not occur due to the formation of a magnetic path.
From this point of view, if the nitrided layer 38a is formed by soft nitriding, the push rod 38 retains the properties of a non-magnetic material, so there is an advantage that leakage magnetic flux does not occur.

Next, FIG. 3 is a sectional view of a pressure regulating valve showing another embodiment of the present invention, and FIG. 4 is a partially cutaway side view of a push rod of the pressure regulating valve.

In FIG. 3, reference numeral 100 denotes a pressure 1 regulating valve, which consists of a pressure regulating valve section 102 and an electromagnet section 103, as in the first embodiment. The ill-valve pressure valve 02 is composed of a valve sleeve 104 and a spool valve 105.

In the pressure regulating valve 100, 106 is a spring;
107 is a large diameter hole that accommodates the spring 106;
8 is a small-diameter guide hole, and 109 is a medium-diameter guide hole.

Also, 121 is a supply port, 122 is an output port, 123
is a discharge port, and the valve sleeve 104 has annular notches 121a and 1 as parts of the ports 121 and 123.
23a.

134a and 135a are formed.

The spool valve 105 has equal diameter land portions 131 and 132.
and a small diameter land portion 133, the valve sleeve 10
4, a space 134 and a closed space 135 are formed.

A feedback oil passage 1 is provided in the land portion 131.
36 are formed. In addition, 137 is a protrusion, 138
1 is a push rod, 139 is a rod-shaped portion, 141 and 187.

189 is a stopper.

The spring 106 is adjusted by screwing the male threaded member 143 into the female threaded member 151. Here, 143a is a locking hole, 144 is a fitting pin, 144a is its lower end, and 145 is a hole. be.

Reference numerals 153 and 154 are flanges of the valve sleeve 104 and the electromagnet 103, respectively, and by caulking the end 156 of the case 155, both flanges 15
3, 154 are connected. Here, 157 is a step, 1
61 is a thick part, 162 is a thin part, 163 and 166 are tapered parts, 164 is a peripheral part, and 165 is an annular step.

Further, the electromagnet section 103 includes a stationary section consisting of a cylindrical core 181 and a coil assembly 182, and a plunger 18.
4 and a push rod 138.

In the core 181, 183 is a hollow part, 184a is a recessed part, 184b is an outer peripheral part, 185 is a sleeve, 186 is a linear 9 rolling bearing, 190 is a bearing cage, 191 is a ball accommodated in the bearing cage 190, and 193 is an abutment part, 194 is a ring made of nonwoven fabric, 195
196 is a connector, 196 is an oil hole, and 197 is a lid member.

7. In this embodiment, the structure of the spool valve 105 in the pressure regulating valve section 102, the structure of the valve sleeve 104, and the structure of the joint between the pressure regulating valve section 102 and the electromagnet section 103 are different from the first embodiment.7. (There are.

That is, the valve sleeve 104 has a large-diameter hole 107 accommodating the spring 106 in its internal axial direction, followed by a small-diameter guide hole 108 and a medium-diameter guide hole 109 that slide and guide a spool valve 105, which will be described later. is formed so as to penetrate through it.

On the outer periphery of the valve sleeve 104 corresponding to the guide hole 109, a supply port 121, an output port 122, and a discharge port 123, which are opened in the radial direction, are formed in order from right to left to ensure smooth fluid flow in each of these ports. Annular cutouts 121a, 123a,
134a and 135a are formed.

The spool valve 105 also has two lands 131 with equal outer diameters that are slidably guided in the medium diameter guide hole 109.
, 132, and a small-diameter land portion 133 adjacent to one of the land portions 131 and slidably guided in the small-diameter guide hole 108. The distance between the opposing ends of the land portions 131 and 132 having the same diameter is such that the output port 122 can communicate alternately with the supply port 121 and the discharge port 123 at a predetermined ratio by sliding the spool valve 105. is formed.

Also, the space 13 between the lands 131 and 132 having the same diameter
4 is always communicated to the output 22.

Then, the one land portion 131 and the small diameter land portion 13
A sealed space 135 formed by the guide holes 108 and 109 is communicated with the space 134 between the lands 131 and 132 through a feedback oil passage 136. The feedback oil passage 136 is formed to diagonally penetrate the land portion 131, and feeds back the output pressure obtained at the protrusion 22 and supplies it to the sealed space 135.

Note that the protruding portion 1 from the center of the end surface of the small diameter land portion 133
Reference numeral 37 is a contact portion with a push rod 138 of the electromagnet portion 103, which will be described later, and a rod-shaped portion 139 standing up from the center of the end surface of the land portion 132 is a contact portion with the push rod 138 of the electromagnet portion 103, which will be described later.
This is a stroke limiting member of the spool valve 105 that also serves as a guide.

By the way, in the hole 145 of the valve sleeve 104, there is a female screw member 1 for applying a load to the spring 106.
51 is formed, and a male screw member 143 that screws into the female screw member 151 is provided. Then, by rotating the male screw member 143 and inserting it into the hole 145, the spring 106 is inserted into the spool valve 105.
By adjusting the amount of rotation of the male screw member 143, the spring 10 can be pressed against the end face of the spring 10.
6 compression amount can be adjusted.

When assembling the pressure regulating valve section 102, first, the spool valve 105 is inserted from the left side into one end of the valve sleeve 104 in which the small diameter guide hole 108 is formed, with the small diameter land section 133 facing. The spring 106 is inserted from the hole 145 side so as to surround the rod-shaped portion 139 and come into contact with the end surface of the land portion 132.

Then, while holding the spring 106, the male threaded member 143 is inserted into the female threaded member 151 of the valve sleeve 151.
By screwing into the spring 106, the spring 106 is compressed by a predetermined amount.

Furthermore, in the structure of the joint between the pressure regulating valve section 102 and the electromagnet section 103, the linear 9 rolling bearing 186 accommodated in the sleeve 185 of the electromagnet section 103 is connected to the push rod 13.
Stopper 141 consisting of a disc spring provided at the left end of 8
The sleeve 185 can freely slide inside the sleeve 185 while being restricted by a brass stopper 189 provided on the plunger 184 side. In addition, stopper 1
41 is provided with a nonwoven fabric member 142 on the pressure regulating valve portion 102 side. This member 142 made of nonwoven fabric is the retaining ring 16
It is fixed by 7.

Since the present embodiment has the above-described configuration, when pressure fluid, such as pressure oil, is supplied from a pump or the like to the supply port 21 of the valve sleeve 104, the pressure oil is supplied from the supply port 121 to the valve sleeve 104 and the spool. Land portion 13 of valve 105
1, and reaches between the land portions 131 and 132 of the spool valve 5 through the opening formed between the land portion 131 and the land portion 131.
, 132, the output port 122 of the valve sleeve 104 is supplied to each hydraulic device in a hydraulic system that requires pressure oil, such as an automatic transmission.

The pressure P of the pressure oil output at the output port 122 is simultaneously returned via the feedback oil passage 136 and is formed by the land portion 131 , the small-diameter land portion 133 adjacent thereto, and the valve sleeve 104 . The cross-sectional area A of the land portion 131 is guided into the sealed space 135.
It is applied to the area difference A + A z obtained by subtracting the cross-sectional area A2 of the small diameter land portion 133 from 1.

The force (AI − At ) P generated by this pressure is
A force F, generated by the electromagnet section 103. , and therefore the spool valve 105 receives this resultant force (AI
At)P+F,. , is pushed to the left in the figure.

Then, the spool valve 105 moves to a position where this resultant force and the force Far pressed by the spring 106 are balanced.
There will be a sliding displacement within the valve sleeve 104.

In this way, the lands 131 and 132 move due to the sliding displacement of the spool valve 105, and the valve sleeve 104
The supply port 121 and the discharge port 123 are controlled to open and close at a predetermined ratio with respect to the output port 122, and as a result, the output pressure P at the output port 122 is lower than that of the electromagnet section 103.
In response to the input electromagnetic signal, P-(Fsp-F3
It is controlled to become ゜L)/(AI-Az).

In the pressure regulating valve configured in this manner, a push rod 138 that applies a load to the spool valve 105 provided in the tTd1 stone portion 103 is arranged in the same way as described above, and as shown in FIG. By subjecting the surface to soft nitriding treatment to form nitride 11138a, it is possible to enhance the bearing function similar to that described above and to maintain the properties as a non-magnetic material.

Note that the present invention is not limited to the above embodiments,
Various modifications are possible based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a pressure regulating valve showing an embodiment of the present invention, Fig. 2 is a partially cutaway side view of a push rod of the same pressure regulating valve, and Fig. 3 is a pressure regulating valve showing another embodiment of the present invention. Cross-sectional view of the regulating valve, No. 4
The figure is a partially cutaway side view of the push rod of the pressure regulating valve, and FIG. 5 is a sectional view of the push rod and plunger of the conventional pressure regulating valve. 1.100...Pressure regulating valve, 2.102...Pressure regulating valve section, 3.103...Electromagnet section, 4,104...Valve sleeve, 5゜105...Spool valve, 6.106・・・
・Spring, 21°121... Supply port, 22.
122... Output port, 23° 123... Ejection port, 31.32.131, 132... Land portion, 3
3.133...Small diameter land portion, 36.136...Feedback oil path, 38.138-...Push rod, 38
a, 138a-Nitride layer, 55.155...Case, 81.181...Core, 82°182...Coil assembly, 84.184...Plunger.

Claims (3)

[Claims] (1) By applying a load from an electromagnet, a spring load, and an output pressure feedback load to a spool valve that slides inside a valve sleeve that has a supply port, an output port, and a discharge port, and balancing these loads,
In a pressure regulating valve configured to adjust supply pressure to an output pressure corresponding to an input electric signal to an electromagnet part and output it,
A pressure regulating valve in which a surface of a push rod of an electromagnetic part that applies a load to the spool valve is subjected to soft nitriding treatment. (2) The pressure regulating valve according to claim 1, wherein the push rod is made of stainless steel. (3) The pressure regulating valve according to claim 1, wherein a ball held by a bearing cage is in contact with the surface of the push rod.