JPS58203525A - Pressure-reducing valve - Google Patents

Abstract

PURPOSE:To omit a drain pipe, by penetrating a coupling hole to couple a pressure room arranged on the other end of a spool with a watercourse on the inlet side through a check valve element into the spool. CONSTITUTION:One end 21 of the spool 1 is pressed like a spring by spring members 16. Against the pressing force of the members 16, pressure Po on the outlet side is applied to the other end 30 of the spool 1 throuch a connection hole 29 or the like to press the other end in the opening direction of a valve. The check valve element 38 premitting flow only in one direction from the outlet side to the inlet side is built in the spool 1 at its axial direction in addition to the spring members to press the check valve element 38 to a valve seat part like a spring. In addition, the coupling hole to connect the pressure room 27 on the other end of the spool 1 with the watercourse on the inlet side throuch the valve element 38 is penetrated into the spool 1.

Description

[Detailed description of the invention] The present invention relates to a pressure reducing valve.

Generally, the pressure reducing valve (a) is used in a circuit as shown in Fig. 1, in which one hydraulic pump (d) operates multiple hydraulic cylinders (
b) (c) is operated to expand and contract at different operating setting pressures. By the way, the conventional pressure reducing valve (a), as shown in FIGS. 2 and 1, has a main pipe connected to an inlet (e) and an outlet (f), as well as an outlet (f
) required a drain pipe (i) for partially refluxing the pressure liquid to the oil tank (h). For this reason, conventionally there have been inconveniences such as the need to install the pressure reducing valve (a) near the oil tank (h), or there have been disadvantages in that the piping work is troublesome due to the drain piping.

The present invention aims to eliminate such conventional drawbacks, and the present invention is characterized in that one end of the spool is open to atmospheric pressure and a resilient member is provided to press and bias the one end in the valve opening direction. Further, the pressure chamber corresponding to the other end of the spool and the outlet side flow path are communicated and connected through a communication hole, and the pressure chamber corresponding to the other end of the spool is connected to the other end of the spool by resisting the pressing force of the resilient member. The spool has an inverted valve body in the axial direction of the spool, which presses the valve in the closing direction by applying pressure on the outlet side and allows flow in only one direction from the outlet side to the inlet side. A connecting hole is provided through the spool to communicate and connect the pressure chamber on the other end side of the spool with the inlet side flow path via a check valve body, and the drain piping is omitted.

Hereinafter, the present invention will be explained in detail based on illustrated embodiments.

In Fig. 3 showing the overall cross section and Fig. 4 showing a partial enlargement of the spool (1), (2) is the valve body, and the fitting part in which the spool (1) is slidably inserted is shown. A hole (3) is provided through the hole (3), and a main flow path (6) consisting of an inlet side flow path (4) and an outlet side flow path (5) is provided to intersect with the #fitting hole (3). . The intersection of the inlet side flow path (4) and the fitting hole (3) is the large diameter part (C), and the intersection of the outlet side flow path (5) and the fitting hole (3)
) is also a large diameter part (8), and the spool sliding part (9) is arranged on the left and right in between.

Also, in Figure 3, there is a sealing material (
Another spool sliding part U having a recessed groove 111 into which the number 1() is fitted is provided, and then a large diameter screw hole part 114) is formed with a stepped part 03. The mark is the elastic member Qe
It is a cylindrical body that houses a cylindrical body, and has a threaded portion on the outer circumferential surface of the opening side, and is mounted by screwing this into the threaded hole α. A set bolt [171] is attached to the bottom of the left side of the cylindrical body 05 so as to be able to be screwed forward and backward, and a small hole stopper for ventilation communicating with the atmosphere is provided therethrough. 191■ is a member for receiving the left and right ends of the elastic member αG, one of the receivers is pressed by the inner end of the member (19 is a set pole) f171, and the other receiver is the member's - One end of rule (1) (2)
) in constant contact with the spool (1) as shown in Figure 3.
When it slides most to the right, it abuts against the stepped portion 03. In this way, one end of the spool (1) is open to atmospheric pressure, and the elastic pressing force is freely adjustable, so that the elastic member αG is operated in the valve opening direction (rightward in FIG. 3) vC. It is elastically pressed and biased.

Thus, another slab sliding part is formed on the right side of the large diameter part (8), and a stepped part and the outside of the screw hole are formed on the right side thereof. The prisoner is the plug and the sealing material (
26) is screwed into the screw hole in a sealed manner, and a pressure chamber in the form of a small diameter blind hole is recessed in the inner end surface of the plug device. A small hole (to) is provided in the radial direction to communicate and connect the pressure chamber and the outer circumference, and further connects the outer circumference of the inner end of the plug (1) and the outlet side flow path (5) of the communication hole Connected at . Therefore, the other end (30) of the spool (1) corresponds to the pressure chamber of the plug, and the pressure chamber is connected to the outlet side flow path (5) by the small hole and the communication hole.
It is connected in communication with. It is also preferable to form a groove in the radial direction on the inner end surface of the plug (2) in place of the hole (V) in the small hole example.

-! 311 is an adapter, through which a passage 321 is provided which is connected and communicated with the outlet side passage (5) of the valve body (2);
A secondary pipe j331 is connected to the opening of this flow path 3Z. Further, a downstream piping cape is connected to the inlet side flow path (4).

Therefore, the spool (1) has large-diameter sliding land portions sh f36+ fa forces at three locations, the left and right ends and the middle,
Each.

It can slide on the spool sliding part Cl2) 122) t91. Then, the intermediate land portion 37, the intermediate spool sliding portion (9), and the spool (1
) move to the left and reach a fully closed state where they slide into contact with each other, the valve action of the spool (1) is performed, and the pressure is lower than the inlet side pressure fPi) of the downstream piping 34). This is to maintain the outlet side pressure (Po). and.

One end of the spool (1)) is resiliently pressed and biased by a resilient member αυ, but the other end of the spool (1) +30) r is communication hole 1
．． 29) etc., the outlet side pressure fP,) acts to push the valve in the closing direction, but as is clear from Fig. 4, the flow only flows in one direction from the outlet side to the inlet side. A check valve body 1'18) that allows this is included in the narrow direction of the spool (1), and a resilient member (support) is also included in the same way,
The inverted valve body spear 8) is elastically pressed against the valve seat (40). and the spool (1) via the check valve body (38).
A connecting hole (411) is provided through the spool (1) to communicate and connect the pressure chamber on the other end (1) side with the inlet side flow path (4).

Specifically, a blind hole (4z) is provided in the axial direction from the other end ■ side of the spool (1), and a small diameter portion (43) between the land portion f37 of the spool (1) is provided with a blind hole (4z). A small diameter radial hole that opens) is provided. First, store the elastic member 4391 in the back of the blind hole, and then move on to the upside-down valve body! , 381
Then, the threaded portion +46 of the valve seat body A71 which has a hole i4θ in the meticulous direction and has a threaded portion (46)
) is screwed into the threaded part of the hole 421 ((c) and installed in an inserted manner. The inner end opening of the hole in the valve seat body II corresponds to the valve seat part (7), In addition, the communicating hole -〇 consists of the hole ■, the inner half of the hole 0 gong, and the hole ming.

Due to the configuration described above, conventional drain piping is completely omitted.]
ing. When a liquid such as oil or water is flowing from the outlet side to the outlet side, if the outlet side pressure (Po) becomes higher than the setting 11, the pressure (Po) passes through the communication hole to the spool (1). It acts on the other end (end) and presses it, and moves it to the left in the figure against the elastic urging force of the elastic member OQ. At this time, the outer flange-shaped land part c of the spool (1) approaches the spool sliding part (9) and narrows the flow path, so the outlet 1j side 1
C force (PO) drops to the set pressure, and conversely, if it becomes lower than the set pressure, the spool (1) moves to the right and the land part (b) moves away from the sliding part (9). The flow path is enlarged and the first measured pressure (Pθ increases by L).

In addition, in the case where the secondary side piping a is connected to, for example, a hydraulic cylinder and the cylinder is operated in the shortening direction, first, the primary side piping (a) is connected to the tank using a switching valve (not shown), and the pressure is increased. When approaches zero, the land portion G'l+ contacts the spool sliding portion (9) and closes the flow path, preventing reverse flow from here. The pressure that presses the reverse check valve body in the left direction in Fig. 6 is applied through the communication hole and the pressure chamber (271, etc.), and the check valve body (toward) moves to the left. From the hole (2), it passes through the flow path (4) on the person 1 side, and then returns to the tank from the next side piping (2), allowing the cylinder marked I to be operated in a shortened manner. ) and check valve body (c), when the pressure in the artificial side flow path (4) is close to zero,
It serves to allow reflux (backflow) from the outlet side flow path (5).

As described in detail above, the present invention provides one end of the spool (1).
υ is open to the atmosphere I'F, and the direction of the valve is
An elastic member (lfD) is provided to press and bias the spool (1), and a pressure chamber (c) corresponding to the other end of the spool (1) is provided, and an outlet side flow path (5) is provided. are connected to each other through a communication hole, and an outlet side pressure (Po) is applied to the other end (9) of the spool (1) against the pressing force of the resilient member α0 to open the valve. A check valve body 138) that is pressed in the closing direction and allows flow in only one direction from the outlet side to the inlet side is attached to the spool (1
) in the axial direction, and the reverse upward valve body l38)
A connecting hole (41) is provided through the spool (1) to communicate and connect the pressure chamber mouth on the other end ■ side of the spool (1) with the inlet side flow path (4), and a drain pipe is connected to the spool (1). Because I omitted it.

This is a pressure reducing valve that can be easily incorporated into any type of hydraulic circuit, simplifying piping, and when the pressure reducing valve and liquid tank are installed far apart, such as in special work vehicles. This is extremely convenient.

Moreover, if the inlet side of the pressure reducing valve is switched to the liquid tank, 5
The spool (1) is in the closed state, but in this state.

It is possible for the liquid in the vessel to flow back to the outlet side secondary piping (one check valve body between the communication hole and the pressure chamber, 38) and the connection hole (41), and to the 111 secondary inlet side. When used in place of the pressure valve shown in the figure, it is convenient because the cylinder (b) can be shortened.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing a conventional example, Fig. 2 is a sectional view of a conventional pressure reducing valve, Fig. 3 is a sectional view showing an embodiment of the present invention, and Fig. 4 is a sectional view showing an embodiment of the present invention.
The figure is an enlarged view of the main parts. (1)... Spool, (5)... Outlet side flow path, αG
- Resilient member 5a... one end, downward pressure chamber, vessel... communication hole, (31B... other end, (38)... check valve body,
+411...Connecting hole. Patent applicant: Kyokuto Kaihatsu Kogyo Co., Ltd. Agent
Patent Attorney Takeshi NakataniFigure 1Figure 2Figure 3Figure 4

Claims (1)

[Claims] 1. One end of the spool (1) is opened to atmospheric pressure, and a resilient member α presses the opening of the one end in the direction of opening the valve.
Further, the pressure chamber So corresponding to the other end (2) of the spool (1) and the outlet side flow path (5) are connected in communication through a communication hole, and the resilient member αG is suppressed. Pressure on the outlet side (Po) is applied to the other end of the spool (1) against the force to press it in the direction of closing the valve, and to allow flow in only one direction from the outlet side to the inlet side. The spool (1) has an internal space between the regurgitation valve elements (between the regurgitation valve elements) in the axial direction of the spool (1), and the regurgitation valve element (
A connecting hole υ is provided through the spool (1) to communicate and connect the pressure chamber ■ on the other end ■ side of the IJ and the inlet side flow path (4) through the spool 381, and the drain piping is omitted. A pressure reducing valve characterized by: