JPH10169800A - Low pressure priority shuttle valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide such a structure, easy to machine, as being capable of effectively reducing for passage resistance between an entrance and an exit. SOLUTION: A switching member 20 arranged in a passage 1 has the cuter diameter approximated to the inner diameter of the passage 1 and the pitch larger than the diameter of a raw material to wind a filament 20a thereon. Rigidity is granted to the filament 20a enough to transmit the operation of one poppet 4 (5) to the other poppet 5 (4), so that proper switching function of selecting one at a lower pressure side out of entrances 7, 8 to be connected to a low pressure priority exit 6 can be provided. Additionally, a space 1a in a wide passage existing inside the filament 20a is communicated with the low pressure priority exit 6 via a gap 20X to the filament 20a open to a circulation position to greatly reduce flow passage resistance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to various hydraulic equipment,
Alternatively, the present invention relates to a low-pressure priority shuttle valve suitably used for a hydraulic system or the like in which the shuttle valve is combined.

[0002]

2. Description of the Related Art A low-pressure priority shuttle valve has a switching function of selecting a relatively low-pressure inlet from two inlets, connecting to a low-pressure priority outlet, and shutting off a high-pressure inlet. It is widely used in various fields. As shown in FIG. 3, a conventional general valve structure includes a pair of seats 2 and 3 facing each other along a passage 1 and a pair of poppets 4 and 5 detachable from the seats 2 and 3. A low-pressure priority outlet 6 whose one end is open to the passage 1 and an inner end of each poppet storage space 4.
a, 5a, and a switching member 9 slidably disposed in the passage 1 and having a longitudinal dimension greater than the separation distance between the sheets 2, 3. . In the drawing, reference numerals 10 and 11 denote springs that elastically bias the poppets 4 and 5 toward the sheets 2 and 3.

In the shuttle valve having such a structure, when both inlets 7 and 8 are at a low pressure, the left and right poppets 4 and 5 are urged by springs 10 and 11 to switch the switching member 9.
However, since the longitudinal dimension of the switching member 9 is larger than the separation distance between the sheets 2 and 3, both the poppets 4 and 5 are located at positions where a certain gap is maintained with respect to the sheets 2 and 3. Will be retained.

[0004] From this state, if it is assumed that high-pressure fluid flows into the inlet 7 and the inlet 8 is relatively lower in pressure than the inlet 7, it is disposed in the poppet storage space 4a communicating with the inlet 7 on the high-pressure side. The poppet 4 is seated on the seat 2 as shown in FIG. 4 to block the inlet 7 from the low-pressure priority outlet 6. At this time, the switching member 9 is pushed by the seating operation, and the poppet 5 arranged in the poppet storage space 5a communicating with the inlet 8 on the low pressure side is urged. The inlet 8 is connected to the low-pressure priority outlet 6 via the passage 1. This operation is the same when the high-pressure fluid flows into the inlet 8 and the inlet 7 has a relatively lower pressure than the inlet 8. In this way, the shuttle valve exhibits a switching function of always selecting the low pressure side of the inlets 7 and 8 and connecting to the low pressure priority outlet 6.

[0005]

By the way, in the conventional structure, a piston is exclusively used for the switching member 9 described above. However, when the columnar piston 9 is simply disposed in the passage 1, the passage 1 is closed, and the fluid flowing from the gap between the poppet 4 (5) and the sheet 2 (3) slides between the piston 9 and the inner wall of the passage 1. Since the connection to the low-pressure priority outlet 6 can be made only through the moving gap, the flow path resistance is large, and an effective switching function cannot be exhibited as it is.

Therefore, conventionally, as shown in FIG. 5, a notch 9a is provided along the longitudinal direction at an equiangular position on the circumference of the piston 9 to secure a clearance between the notch 9a and the inner wall of the passage 1. As shown in FIG. 6, a countermeasure is taken to form an internal passage 9b open at both end faces at the axial center position of the piston 9. However, in the former case, since the fluid flows only through the notch 9a facing the low-pressure priority outlet 6 and the fluid does not flow into the other notches 9a, the effect of reducing the flow path resistance is not sufficiently obtained, and the switching member is not provided. 9 is not particularly prohibited from rotating around the axis, there is also a disadvantage that the flow path resistance varies depending on the position on the circumference of the switching member 9 where the notch 9a rotates. is there. In this case, it is conceivable to further increase the size of the notch 9a. However, since the contact position between the outer periphery of the piston 9 and the inner wall of the passage 1 becomes extremely limited, a guide when the piston 9 slides in the passage 1 is provided. Action will be reduced and cause malfunction.
Even if the cutouts 9a are communicated with each other through the small holes, the processing simply becomes complicated. On the other hand, in the latter case, since the internal passage 9b is closed by the poppets 4 and 5 as it is, another internal passage 9b near the end face is further released to a position not closed by the poppets 4 and 5. As in the case where the small holes 9c are required, a remarkable burden is imposed on the processing.

The present invention has been made in view of such a situation, and has a structure capable of facilitating machining and effectively reducing flow resistance between an inlet on a low pressure side and a low pressure priority outlet. It aims to realize a low pressure priority type shuttle valve.

[0008]

In order to achieve the above-mentioned object, the present invention provides a shuttle valve having a general configuration as a shuttle valve of this kind, wherein the switching member is configured such that an outer diameter is changed to an inner diameter of a passage. It is characterized in that it is formed by winding the striated body so as to substantially match and take a pitch larger than the material diameter.

With such a configuration, if the striated body has such a rigidity that the movement of one poppet can be transmitted to the other poppet, the same switching function as the conventional one can be exhibited. In addition to this, there is a vast passage space inside the striated body, and this passage space communicates with the low-pressure priority outlet through a gap between the striated bodies that open at the orbital position. The flow resistance between the inlet on the side and the low-pressure priority outlet can be made much smaller than in the past, and the flow resistance can always be kept at a constant level.
In addition, since it can be formed by simply winding the striated body, the processing becomes extremely simple, and any circulating position can be brought into close sliding contact with the inner wall of the passage, so that it can be slid in the passage. Can be secured smoothly.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. The low pressure priority type shuttle valve according to this embodiment has a structure basically similar to that shown in FIGS. That is, this device has a pair of sheets 2 and 3 opposed to each other with a passage 1 therebetween, a pair of steel ball poppets 4 and 5 detachable from the sheets 2 and 3, and an inner end in the passage 1. A low-pressure priority outlet 6 that opens, a pair of inlets 7 and 8 whose inner ends communicate with the poppet storage spaces 4a and 5a, and a slidably disposed longitudinally spaced passageway 1 between the sheets 2 and 3. And a switching member 20 set to be larger than the distance.

In this embodiment, the switching member 20
And a structure different from the conventional one. That is, the switching member 20 does not have a conventional piston shape, but has a coil spring shape, and has a wire whose outer diameter substantially matches the inner diameter of the passage and whose pitch is larger than the material diameter. It is configured by spirally winding the strip 20a. The material of the striated body 20a may be the same as that of a general spring or the like, and its material diameter is switched when the operation of one poppet 4 (5) is transmitted to the other poppet 5 (4). The rigidity is set so that the dimensional change occurring in the longitudinal direction of the entire member 20 does not adversely affect the switching function in practical use.

In such a case, the switching member 20 is normally in the neutral position shown in FIG. 1, and thereafter, when the inlet 7 becomes high pressure and the inlet 8 becomes low pressure as shown in FIG. The member 20 is capable of transmitting the seating operation of the poppet 4 to the poppet 5 to separate the poppet 5 from the seat 3 in the same manner as the conventional piston type, and operates properly even when the high / low pressure is reversed. And the entrance 7, 8
The proper switching function of always selecting the low pressure side and connecting to the low pressure priority outlet 6 can be properly performed.

In addition, when the switching member 20 of this embodiment is used, the passage space 1a exists inside the striated body 20a,
Since this passage internal space 1a communicates with the low-pressure priority outlet 6 through the gap 20X between the materials opened at the orbital position, the flow path resistance between the low-pressure side inlets 7, 8 and the low-pressure priority outlet 6 is lower than that of the conventional one. The flow path resistance can always be kept at a constant level. In addition, since the striated body 20a is spirally wound at a constant pitch to a certain extent, and a somewhat high-precision end treatment for precisely defining the longitudinal dimension only on the end face is basically required, FIG. The processing is much simpler than the conventional switching member 9 shown in FIG. 6, and the man-hour and cost for manufacturing the shuttle valve can be significantly reduced. Furthermore, since any circling position can be brought into close sliding contact with the inner wall of the passage, a smooth behavior when sliding inside the passage 1 can be ensured.

The specific configuration of each section is not limited to the illustrated embodiment, and various modifications can be made without departing from the spirit of the present invention.

[0015]

According to the present invention, as described above, a switching member having a spiral or similar structure is used for a switching member which plays a role of transmitting the movement of a poppet performing a sitting operation by high pressure to the other poppet. It was done.
Therefore, while ensuring proper operation as the switching member, the flow path resistance when the fluid flows by connecting the low-pressure side inlet and the low-pressure priority outlet is extremely low, and the function as the switching valve is effectively performed. It is possible to increase. Moreover,
Since the switching member of the present invention can be formed by a simple process simply by bending and forming the striated body, the man-hour and cost of the switching member and, consequently, the entire shuttle valve can be greatly reduced as compared with the related art. It becomes possible.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is an operation explanatory view corresponding to FIG. 1;

FIG. 3 is a sectional view showing a conventional example.

FIG. 4 is an operation explanatory view corresponding to FIG. 3;

FIG. 5 is a perspective view showing a modification of a switching member in a conventional example.

FIG. 6 is a perspective view showing a modification of a switching member in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Passage 2, 3 ... Sheet 4, 5 ... Poppet 6 ... Low pressure priority outlet 7, 8 ... Inlet 20 ... Switching member 20a ... Striatal body

Claims (1)

[Claims] 1. A pair of sheets facing each other along a passage, a pair of poppets detachable from these sheets, a low-pressure priority outlet having an inner end opened to the passage, and an inner end provided in each poppet storage space. A pair of inlets communicating with each other, and a switching member slidably disposed in the passage and having a longitudinal dimension set to be larger than the separation distance between the sheets, one of the inlets having a relatively high pressure, When the other becomes low pressure, and the poppet arranged in the poppet storage space communicating with the high pressure side inlet sits on the seat and shuts off the inlet from the low pressure priority outlet,
The seating operation is transmitted to the poppet arranged in the poppet storage space communicating with the low pressure side inlet via the switching member,
The poppet is separated from the sheet so that the inlet is connected to the low-pressure priority outlet via a passage. The switching member has an outer diameter substantially matching an inner diameter of the passage and a pitch larger than a material diameter. A low pressure priority type shuttle valve characterized by being constructed by winding a striated body.