JP4686143B2 - Hydraulic control valve - Google Patents

Description

  The present invention relates to an improvement of a ball-type hydraulic control valve using a ball as a valve body.

  Conventionally, as this type of hydraulic control valve, for example, a hydraulic control valve 1 shown in FIG. 7 includes a spherical ball 2 that controls the flow of hydraulic fluid against the seat 40 and a ball support that supports the ball 2. 30 and a spring 5 that presses the ball 2 against the seat 40 via the ball support 30. When the differential pressure across the ball 2 rises above a predetermined value, the ball 2 lifts from the seat 40 while compressing the spring 5, and the working fluid passes through the seat 40 and into the main body 20 as shown by the arrows in the figure. Flowing.

  The ball support 30 is formed with a flange 32 that defines the secondary pressure chamber 8 between the ball support 30 and the annular flow path 10 between the outer peripheral surface of the flange 32 and the main body 20. When the ball 2 is lifted, the annular flow path 10 gives resistance to the flow of the hydraulic fluid flowing out from the secondary pressure chamber 8, whereby the pressure in the secondary pressure chamber 8 is increased, and the fluid pressure control valve 1. The override characteristic indicating the relationship between the pressure and the flow rate can be arbitrarily set.

Further, the hydraulic control valve disclosed in Patent Document 1 is configured to prevent the lateral vibration of the ball and the ball support by bringing the outer peripheral surface of the ball support into sliding contact with the inner peripheral surface of the main body.
JP 2002-39412 A

  However, in the hydraulic control valve 1 shown in FIG. 7, when the gap between the outer peripheral surface of the flange portion 32 and the main body 20 is large, if the flow of hydraulic fluid flowing through the annular flow path 10 becomes uneven in the circumferential direction, There was a possibility that the ball support 30 would vibrate and generate noise.

  And since the annular flow path 10 is defined between the outer peripheral surface of the collar part 32 and the inner peripheral surface of the main body 20 facing each other substantially in parallel, if this gap is reduced, the pressure drop characteristic is activated here. There is a problem of parallel gap flow characteristics that are easily affected by changes in the viscosity of the liquid, and the performance of the hydraulic pressure control valve changes greatly according to changes in the temperature of the hydraulic fluid.

  Moreover, since the hydraulic control valve disclosed in Patent Document 1 causes the outer peripheral surface of the ball support to slide in contact with the inner peripheral surface on the main body side, hysteresis due to friction increases, and the static characteristics of the hydraulic control valve are reduced. There was a problem of getting worse.

  In this hydraulic control valve, if the clearance between the ball support and the main body is increased to improve the slidability of the ball support, the ball and the ball support may laterally vibrate and generate noise. .

  The present invention has been made in view of the above problems, and it is an object of the present invention to prevent lateral vibration and noise of a ball in a ball-type hydraulic control valve.

  The present invention relates to a sheet interposed in a flow path through which liquid flows, a spherical ball that controls the flow of liquid against the sheet, a ball support that supports the ball, and an axial direction of the ball support in the axial direction. And a spring for pressing the ball against the seat via the ball support, an upstream pressure chamber defined on the upstream side of the seat, and a space defined between the seat and the ball support. The present invention is applied to a ball-type hydraulic pressure control valve including a secondary pressure chamber and a downstream pressure chamber defined on the downstream side of the ball support.

A plurality of protrusions slidably contacting the inner peripheral surface of the housing portion and a plurality of grooves extending in the axial direction of the ball support are formed between the protrusions on the outer periphery of the ball support. A support orifice that communicates the secondary pressure chamber and the downstream pressure chamber is formed between the peripheral surfaces, and each projection extends in the axial direction with a substantially equal interval in the circumferential direction of the ball support, and each projection is a receiving portion. The contact area with respect to the inner peripheral surface of each groove is formed so that the opening of each groove is smaller than the non-contact area facing the inner peripheral surface of the housing portion, and the ball support is formed in a conical shape formed on the ball support so as to seat the ball Has a lead-in part that protrudes upstream from the recessed ball seat , and the bottom of the groove is notched at the part of the lead-in part to form a gap between the lead-in pressure chamber and each support orifice. The liquid flow is secondary That the force chamber and configured to be narrowed in the course of flow into each support orifice through each gap was assumed to be characterized.

  When the differential pressure across the ball rises above a predetermined value, the hydraulic pressure control valve lifts the ball from the seat while compressing the spring, so that the hydraulic fluid is in the upstream pressure chamber, secondary pressure chamber, support orifice, downstream Flows through the side pressure chamber.

  At this time, the ball support is guided so as to move coaxially with the seat as each protrusion slides on the inner peripheral surface of the housing portion, and the ball and the ball support are restrained from vibrating laterally in the radial direction. Can be prevented.

  Each protrusion extends in the axial direction at substantially equal intervals in the circumferential direction of the ball support, and forms a support orifice that communicates the secondary pressure chamber and the downstream pressure chamber with the inner peripheral surface of the housing portion. The fluid pressure acting around the ball support can be made uniform, and the frictional force acting on the ball support can be kept small.

  The ball including viscous friction is formed by forming each contact so that the contact area with the inner peripheral surface of the accommodating portion is smaller than the non-contact area where the opening of each support orifice faces the inner peripheral surface of the accommodating portion. The frictional force acting on the support can be kept small.

  For this reason, the hydraulic control valve can suppress an increase in hysteresis in which the valve opening pressure changes due to the frictional force acting on the ball support, and can improve the static characteristics of the hydraulic control valve.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  As shown in FIG. 1, a ball-type hydraulic pressure control valve 1 includes a seat 40 interposed in a flow path through which a liquid flows, and a spherical ball as a valve body that controls the flow of liquid against the seat 40. 2, a ball support 30 that supports the ball 2, and a spring 5 that presses the ball 2 against the seat 40 via the ball support 30.

  The ball-type hydraulic pressure control valve 1 includes a cylindrical main body 20, in which a ball 2, a ball support 30, a spring 5, and the like are housed, and a seat 40 is fixed via a sleeve 39. The main body 20 includes an inner peripheral surface 21 into which a sleeve 39 is fitted, a housing portion 22 that defines a space for housing the ball 2, the ball support 30, and the like, and a through hole 23 that opens to the housing portion 22.

  The sheet 40 has a sheet hole 41 penetrating through the sheet 40, a sheet orifice (diaphragm) 42 formed in the middle of the sheet hole 41, and a sheet surface 43 that is open and recessed in a conical shape. When the ball 2 is seated on the inner peripheral edge of the surface 43, the flow of liquid through the seat hole 41 is stopped.

  The spring 5 is formed by spirally winding a linear spring material. The spring 5 is disposed coaxially with the ball support 30, the ball 2, and the seat 40, and is interposed between the bottom surface 24 of the main body 20 and the ball support 30 while being compressed by a predetermined amount.

  The ball support 30 has a ball seat 31 that is recessed in a conical shape for seating the ball 2 and a spring seat 33 for seating one end of the spring 5.

  The flow path through which the liquid flows in the hydraulic pressure control valve 1 includes an upstream pressure chamber 7 defined on the upstream side of the seat 40, a secondary pressure chamber 8 defined between the seat 40 and the ball support 30, and It is divided into a downstream pressure chamber 9 defined on the downstream side of the ball support 30. When the differential pressure across the ball 2 in the upstream pressure chamber 7 and the downstream pressure chamber 9 rises above a predetermined value, the ball 2 is lifted from the seat 40 while compressing the spring 5, and the liquid is indicated by an arrow in FIG. As shown, it flows through the upstream pressure chamber 7 in the seat 40 to the downstream pressure chamber 9 in the main body 20.

  The ball support 30 includes a plurality of protrusions 37 that are in sliding contact with the inner peripheral surface of the housing portion 22 of the main body 20, and a groove 36 that extends between the protrusions 37 in the axial direction of the ball support 30.

  And although it is a place which makes it the summary of this invention, the support orifice 11 which connects the secondary pressure chamber 8 and the downstream pressure chamber 9 between each groove | channel 36 and the internal peripheral surface of the accommodating part 22 of the main body 20 is formed, and each The protrusions 37 and the grooves 36 extend in the axial direction at substantially equal intervals in the circumferential direction of the ball support 30, and each protrusion 37 has a contact area with respect to the inner peripheral surface of the housing portion 22 of the main body 20. The opening of the orifice 11) is formed to be smaller than the non-contact area facing the inner peripheral surface of the housing portion 22 of the main body 20.

  As shown in FIGS. 2A and 2B, the ball support 30 has a flange portion 34 that expands in a disk shape, and this flange portion 34 is a portion located on the outer periphery from the ball seat 31 of the ball support 30. The outer diameter of the ball 2 is larger than that of the ball 2, and the secondary pressure chamber 8 is defined between the ball 40 and the seat 40.

  As shown in FIG. 2A, each projection 37 has a gear-shaped cross section, and is formed on the outer peripheral portion of the flange portion 34 at a constant pitch. Each projection 37 has a distal end surface 35 that is curved in a cylindrical surface, and the distal end surface 35 is in sliding contact with the inner peripheral surface of the housing portion 22 of the main body 20.

  Each projection 37 has an introduction portion 38 that protrudes upstream from the support orifice 11, and a gap 12 that communicates the secondary pressure chamber 8 and the support orifice 11 is formed between the introduction portions 38, so that the flow of liquid is two. It is configured to flow from the next pressure chamber 8 through the gaps 12 to the support orifice 11.

  Each gap 12 is formed by notching the bottom of each groove 36 at a portion upstream of the ball seat 31. Accordingly, each gap 12 opens to face the ball 2, and a liquid flow that expands in the radial direction along the ball 2 flows into the support orifice 11 through each gap 12.

  The ball-type hydraulic pressure control valve 1 is configured as described above, and when the differential pressure across the ball 2 rises above a predetermined value, the ball 2 is lifted from the seat 40 while compressing the spring 5, and the liquid is drawn. 3 flows to the outside of the main body 20 through the upstream pressure chamber 7, the seat orifice 42, the secondary pressure chamber 8, the support orifice 11, the downstream pressure chamber 9, and the through hole 23.

  At this time, the ball support 30 is guided so as to move coaxially with the seat 40 when the tip surface 35 of each projection 37 is in sliding contact with the inner peripheral surface of the housing portion 22 of the main body 20. Can be prevented from lateral vibration in the radial direction, and noise can be prevented.

  The protrusions 37 and the grooves 36 extend in the axial direction at substantially equal intervals in the circumferential direction of the ball support 30, and the secondary pressure chambers 8 are provided between the grooves 36 and the inner peripheral surface of the housing portion 22 of the main body 20. By forming the support orifice 11 communicating with the downstream pressure chamber 9, the fluid pressure acting around the ball support 30 can be made uniform, and the frictional force acting on the ball support 30 can be kept small.

  The contact area of each protrusion 37 with respect to the inner peripheral surface of the housing portion 22 of the main body 20 is smaller than the non-contact area where the opening of each groove 36 (support orifice 11) faces the inner peripheral surface of the housing portion 22 of the main body 20. By forming so, the frictional force acting on the ball support 30 including viscous friction can be kept small.

  For this reason, the hydraulic control valve 1 can suppress an increase in hysteresis in which the valve opening pressure changes due to the frictional force acting on the ball support 30, and can improve the static characteristics of the hydraulic control valve 1.

  The liquid flowing into the support orifices 11 from the secondary pressure chambers 8 through the gaps 12 is throttled in stages, and the flow of liquid spreading radially along the balls 2 passes through the gaps 12 to the supports. Smooth flow to the orifice 11 can suppress the occurrence of cavitation.

  On the other hand, in the case of the structure having no gap 12, the liquid flowing from the secondary pressure chamber 8 into each support orifice 11 is suddenly throttled and the flow direction changes suddenly. Cavitation is likely to occur in the vicinity of.

  Since the seat orifice 42 and the support orifice 11 are provided before and after the secondary pressure chamber 8, the pressure of the secondary pressure chamber 8 can be adjusted in a wide range by changing the opening area thereof, and the hydraulic pressure control valve 1. The degree of freedom in setting the override characteristics of the.

  The hydraulic control valve 1 may be provided with an orifice on the downstream side of the support orifice 11.

  Next, another embodiment shown in FIGS. 4 and 5 (a) and (b) will be described. In addition, the same code | symbol is attached | subjected to the same structure part as the said embodiment.

  The ball support 30 forms a notch 37b in the middle of each projection 37, and divides the support orifice 11 into an upstream support orifice 11a and a downstream support orifice 11b. An annular channel 11c is formed between the upstream support orifice 11a and the downstream support orifice 11b.

  In this case, the liquid flowing from the secondary pressure chamber 8 toward the downstream pressure chamber 9 is throttled stepwise through the gap 12, the upstream support orifice 11a, the annular flow passage 11c, and the downstream support orifice 11b, and therefore, cavitation. And the temperature characteristics of the hydraulic control valve 1 can be made constant.

  It is possible to set a large dimensional ratio of the introduction portion 38 to the passage length of the upstream support orifice 11a, and to effectively suppress the occurrence of cavitation.

The Rukoto forming shapes the way the notch 37b of each projection 37, reducing the slide contact area with respect to the main body of the housing portion 22 of the ball support 30, it is possible to reduce the frictional force acting on the ball support 30, thereby facilitating dimensional control .

  Next, another embodiment shown in FIGS. 6A and 6B will be described. In addition, the same code | symbol is attached | subjected to the same structure part as the said embodiment.

  The ball support 30 has a substantially hexagonal cross-sectional shape, and has six corners as projections 37. The support orifice 11 is formed in a half-moon shape between the inner peripheral surface of the housing portion 22 of the main body and the outer peripheral surface of the ball support 30.

  A notch 37b is formed in the middle of each projection 37, and the support orifice is divided into an upstream support orifice and a downstream support orifice.

  In this case, the sliding contact area of the main body of the ball support 30 with respect to the housing portion 22 can be reduced, and the frictional force acting on the ball support 30 can be reduced. become.

  In addition, you may form the introduction part which protrudes upstream from a support orifice in the front-end | tip part of each protrusion 37. FIG.

  The present invention is not limited to the above-described embodiment, and it is obvious that various modifications can be made within the scope of the technical idea.

  The present invention can be used for a ball-type hydraulic control valve using a ball as a valve body.

Sectional drawing of the hydraulic-pressure control valve which shows embodiment of this invention. Similarly, (a) is a front view of the ball support, and (b) is a cross-sectional view of the ball support. The schematic diagram of a hydraulic control valve. Sectional drawing of the hydraulic control valve which shows other embodiment of this invention. Similarly, (a) is a front view of the ball support, and (b) is a cross-sectional view of the ball support. 4 shows another embodiment of the present invention, in which (a) is a front view of a ball support, and (b) is a cross-sectional view of the ball support. FIG. The schematic diagram of the hydraulic control valve which shows a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hydraulic pressure control valve 2 Ball | bowl 4 Main body 5 Spring 7 Upstream pressure chamber 8 Secondary pressure chamber 9 Downstream pressure chamber 11 Support orifice 11a Upstream support orifice 11b Downstream support orifice 12 Gap 22 Housing part 30 Ball support 35 Front end surface 36 groove 37 protrusion 37b notch 38 introduction part

Claims (3)

A sheet interposed in a flow path through which liquid flows;
A spherical ball that controls the flow of liquid against this sheet,
A ball support that supports this ball,
An accommodating portion for accommodating the ball support slidably in the axial direction;
A spring for pressing the ball against the seat via the ball support;
An upstream pressure chamber defined on the upstream side of the seat;
A secondary pressure chamber defined between the seat and the ball support;
In a ball-type hydraulic control valve comprising a downstream pressure chamber defined on the downstream side of the ball support,
A plurality of protrusions slidably contacting the inner peripheral surface of the housing portion and a plurality of grooves extending in the axial direction of the ball support are formed between the protrusions on the outer periphery of the ball support. Forming a support orifice communicating the secondary pressure chamber and the downstream pressure chamber between the inner peripheral surfaces of
It said axially extending each projection has a substantially equal intervals in the circumferential direction of the ball support, and the openings of the respective grooves of the contact area each projection with the inner circumference of the housing portion of the housing portion Formed to be smaller than the non-contact area facing the inner surface,
The ball support has an introduction portion protruding upstream from a conically recessed ball seat formed in the ball support so as to seat the ball ,
Forming a gap communicating the secondary pressure chamber and the support orifices between the introduction parts by cutting out the bottom of the groove at a site of the introduction part;
Hydraulic pressure control valve, wherein the flow of liquid is configured to be narrowed in the course of flowing to the each gap through the respective support orifice from the secondary pressure chamber. The gaps open against the balls;
2. The hydraulic pressure control valve according to claim 1, wherein a flow of liquid spreading in a radial direction along the ball flows into the support orifices through the gaps. Forming a notch in the middle of each projection,
3. The hydraulic control valve according to claim 1, wherein the support orifice is divided into an upstream support orifice and a downstream support orifice by the notch.

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