JP2002048252A - Switching valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To constrain occurrence of locking in a switching valve due to foreign particles being trapped between a spool and a port upon the direction control valve equipping a valve body provided with the inflow/outflow port and the spool. SOLUTION: The switching valve 30 is equipped with the valve body provided with a bore of the valve 31 and an inflow/outflow port 36, and the spool 32 including a land 38 and an annular groove 42, and the spool 32 moves in the bore of the valve 31, thereby the outflow port 36 is set in fluid communication with the inflow port via an annular groove 42 and cut off from the inflow port by the land 38. Face of a sidewall 47 on the annular groove 42 and outer peripheral face 40 of the land 38 are connected via tapered face 49 and upon cross section in axial line which is cross section passing through axial line of the spool 32, the tapered face 49 forms an obtuse angle larger than 135 degree between the outer peripheral face 40 and itself; while at the same time, it occupies position abutting on virtual circle C, having a radius with the largest diameter of the foreign particles 70 centralizing edge 62 of the outflow port 36, which forms a restricted fluid passage between the tapered face 49 and the edge, when the spool 32 is moved and mixed in working fluid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to, for example, a plurality of hydraulic oil passages communicating with a pump that discharges hydraulic oil supplied to a hydraulic utilization device. The present invention relates to a switching valve provided with a spool for communicating and blocking an outflow port.

[0002]

2. Description of the Related Art In a positive displacement and constant displacement rotary pump, such as a vane pump or a gear pump, which is a device for generating hydraulic oil supplied to a hydraulic device, the discharge flow rate is proportional to the rotation speed of the pump. Therefore, the discharge flow rate tends to be insufficient in the low rotation speed range, and the discharge flow rate becomes excessive in the high rotation speed range. 2. Description of the Related Art A valve for switching between oil passages is provided in a communicating suction passage or discharge passage to control a discharge flow rate.

For example, Japanese Patent Application Laid-Open No. Hei 10-73084 discloses an oil pump device using a control valve composed of a spool valve as a valve for switching an oil passage. The oil pump device includes an outer rotor, an inner rotor, a plurality of spaces formed between the two rotors, the volumes of which are increased and decreased, an oil pump having a discharge port communicating with the spaces, and two suction ports; A control valve for switching an oil passage of the hydraulic oil in accordance with a rotation speed of the internal combustion engine that drives the oil pump in order to change a discharge flow rate of the hydraulic oil from the pump.

As shown in FIG. 4, the control valve V has a valve body b slidably disposed in an axial direction within a valve chamber a formed in the housing of the oil pump. b is the first
It has a valve portion c and a second valve portion d, and an annular valve passage e formed between the first and second valve portions c and d. On the other hand, valve room a
Has a first intermediate port f communicating with one suction port communicating with the oil storage unit via a suction passage, a second intermediate port g communicating with the other suction port, and a control port h communicating with the discharge path. And are open.

[0005] In the low engine speed range of the internal combustion engine, the valve b
Is at the position shown in FIG. 4A, the second intermediate port g is in communication with the first intermediate port f via the valve passage e by the first valve portion c, and the oil pump is Both suction ports communicate with each other to perform a suction operation from the oil storage unit.
When the rotation speed increases, the valve body b moves to occupy the position shown in FIG. 4B due to the increase in the hydraulic pressure of the control port h, and the second valve portion d partially closes the second intermediate port g. In the other suction port, the hydraulic oil from the oil storage unit is sucked through the throttled second intermediate port g through the valve passage e, and at the same time, the hydraulic oil from the supply passage through the side passage k. Is pumped. When the rotation speed further increases, the valve body b
Moves to occupy the position shown in FIG. 4C, the second intermediate port g is separated from the first intermediate port f by the second valve portion d, and the hydraulic oil from the supply passage passes through the side passage k. To the other suction port.

[0006]

By the way, in the control valve V composed of a spool valve, the gap between the valve chamber a and the valve body b has a lubricating structure for the sliding portion between the valve chamber a and the valve body b. , And is set to be extremely small so that oil leakage between the adjacent ports f and g is minimized. On the other hand, in the hydraulic oil, fine metal particles generated at the time of machining the valve chamber a and the ports f, g, h, etc. are not completely removed and remain as they are, or foreign substances are newly generated during the circulation of the hydraulic oil. When the foreign matter including such metal particles is not captured by the filter, the foreign matter flows through the pump and the oil passage together with the hydraulic oil.

[0007] As in the prior art, the angle of the edge m of the cylindrical second valve portion d is substantially a right angle, and the angle of the edge n of the second intermediate port g is substantially a right angle.
When the valve element b moves from the position shown in FIG. 4 (B) to the position shown in FIG. 4 (C), as shown in FIG. In direction
The so-called lock of the control valve V, which prevents the valve body b from being moved between the edge m of the valve portion d and the edge n of the second intermediate port g, may occur. Therefore, in order to prevent such foreign matter s from being pinched, the valve chamber a
To increase the gap between the valve body b and the ports f and g
The leakage of hydraulic oil between them increases, making it difficult to obtain a desired discharge flow rate characteristic.

The present invention has been made in view of such circumstances, and has a switching valve provided with a spool slidably fitted in a valve hole of a valve body provided with an inflow port and an outflow port. It is an object of the present invention to suppress occurrence of lock of a switching valve due to foreign matter being caught between a spool and a port without increasing leakage of hydraulic oil between ports.

[0009]

According to the first aspect of the present invention, there is provided a valve body having an inlet port and an outlet port which respectively communicate with a valve hole and a plurality of oil passages for hydraulic oil. A spool slidably fitted in the valve hole and having an annular groove provided between a pair of lands, wherein the spool has its axis in the valve hole relative to the valve hole. The relative movement in the direction, the outflow port is communicated with the inflow port through the annular groove, and the switching valve is shut off from the inflow port by any of the lands, the side wall surface of the annular groove And an outer peripheral surface of the land adjacent to the side wall surface is connected via an inclined surface, and the inclined surface is formed such that the valve body and the spool have the outer peripheral surface in an axial cross section passing through the axis. Between 13 While forming an obtuse angle greater than °, when the spool is relatively moved, it is mixed into the hydraulic oil around the edge of the outflow port or the inflow port forming a narrowed flow path with the inclined surface. This is a switching valve that can occupy a position in contact with an imaginary circle whose radius is the maximum diameter of the foreign matter.

According to the first aspect of the present invention, the spool moves relative to the valve body so as to close the outflow port or the inflow port, and the spool moves between the outer peripheral surface of the land and the spool.
When an obtuse angle that forms an obtuse angle greater than 35 ° approaches the edge of a port that forms a narrowed flow path with the incline,
In the axial section, the inclined surface touches the imaginary circle, and then enters slightly inside the imaginary circle. At this time, for example, when foreign matter having the largest diameter mixed in the hydraulic oil tries to pass through the narrowed flow path, the foreign matter is reduced from the portion of the minimum flow path cross-sectional area formed by the inclined surface and the edge. May also be trapped between the inclined surface and the peripheral surface of the edge or valve hole at an upstream position.

When the foreign matter is sandwiched, the angle between the outer peripheral surface and the inclined surface is an obtuse angle larger than 135 °, so that the contact position between the foreign material and the inclined surface, that is, the contact position between the foreign material and the spool, In comparison with the above-described conventional technique, the position is located farther inward in the radial direction from the edge or the peripheral wall surface of the valve hole and closer to the edge in the axial direction. As a result, the degree of the part of the foreign matter protruding into the outflow port or the inflow port is reduced or does not protrude, so that the foreign substance is less likely to be caught in the axial direction between the spool and the port. In addition, due to the inclined surface, when the spool further approaches the edge, of the force of the spool pressing the pinched foreign object toward the valve body, the component force of pressing the foreign object in the axial direction is reduced,
Also in this respect, foreign matter is less likely to be caught in the axial direction between the spool and the port.

A minimum radial gap between the outer peripheral surface of the spool and the peripheral wall surface of the valve hole for supplying a minimum amount of hydraulic oil necessary for lubrication of a sliding portion formed by the surfaces. The spool is inclined with respect to the axial direction due to the uneven force acting on the spool based on the hydraulic pressure of the hydraulic oil of each port, but in this inclined state Even if the spool approaches the edge and the spool abuts on the edge, the edge abuts on the inclined surface where the angle between the outer peripheral surface and the outer peripheral surface is an obtuse angle that is greater than 135 °, so that the spool is caught on the edge. Without being guided by the inclined surface having an inclination angle closer to being parallel to the axial direction, it is smoothly guided.

As a result, even if the foreign matter in the hydraulic oil is caught between the inclined surface of the spool and the edge or the peripheral wall of the valve body by the spool closing the port,
The degree to which the foreign matter projects into the outflow port or the inflow port is reduced or no longer exists, and the component force for pressing the sandwiched foreign matter in the axial direction is also reduced, so that the foreign matter is axially moved between the spool and the port. It becomes difficult to be caught and the occurrence of locking of the switching valve can be suppressed. At this time, there is no need to increase the gap between the outer peripheral surface of the land of the spool and the peripheral wall surface of the valve hole, so that leakage of hydraulic oil between the inflow port and the outflow port does not increase.
Furthermore, even if the spool is in a tilted state, the spool is smoothly moved without being caught by the edge, and the port can be switched quickly.

According to a second aspect of the present invention, in the switching valve according to the first aspect, the inclined surface has a single tapered surface,
The angle of the second edge formed by the tapered surface and the side wall surface is smaller than the angle of the first edge formed by the tapered surface and the outer peripheral surface.

According to the second aspect of the present invention, since the inclined surface is formed by a single tapered surface, the processing for forming the inclined surface is facilitated. In addition, although the angle of the second edge is smaller than the angle of the first edge, and the angle of the first edge is an obtuse angle larger than 135 °, the annular groove is formed by steeply forming the side wall surface. , The flow path cross-sectional area can be increased, and it becomes easy to secure the flow rate of the hydraulic oil flowing from the inflow port in the annular groove.

As a result, the processing for forming the inclined surface is facilitated, the cost of the switching valve can be reduced, and the flow rate of the hydraulic oil in the annular groove can be easily ensured. The present invention can also be applied to an oil passage through which a large amount of hydraulic oil flows, and the application range of the switching valve is widened.

[0017]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
This will be described with reference to FIG. In this embodiment, a constant displacement vane pump 1 is provided in a metal belt type continuously variable transmission for a vehicle as a hydraulic device, and is wound around a variable drive pulley and a variable driven pulley around which a metal belt is wound. It is used as a hydraulic pump that supplies hydraulic oil for changing the radius.

Referring to FIG. 1, which is a plan view of the vane pump 1 as viewed from the mating surface of the body 2, the vane pump 1 includes a body 2, a cover (not shown), a pump unit 3 housed in the cover, and a body. A seal plate (not shown) which is interposed between the cover 2 and the cover and covers an opening of a groove provided on each mating surface of the body 2 and the cover to form an oil passage for hydraulic oil. The seal plate and the cover are fixed to the body 2 together by a plurality of bolts. And
A drive shaft 4 that is rotationally driven by the power of the internal combustion engine is rotatably supported by the body 2 and the cover.

The pump unit 3 has an annular cam ring 5 having a circular outer peripheral surface and an inner peripheral surface having a shape similar to an ellipse.
And a rotor 6 disposed inside the cam ring 5 and rotating integrally with the drive shaft 4, and a plurality of vane grooves 7 provided radially at equal intervals in a circumferential direction of the rotor 6. The vehicle includes a plurality of vanes 8 slidably fitted in directions, and a pair of side plates (not shown) for covering the side surfaces of the cam ring 5 and the rotor 6 on the body 2 side and the side surfaces on the cover side. The tip of each vane 8 is a cam ring 5
Slidably contacts the cam surface 9 formed by the inner peripheral surface of the
A plurality of pump chambers 10 is formed by partitioning a space between the two side plates between the rotor and the outer peripheral surface of the rotor 6 by the plurality of vanes 8.

The cam surface 9 of the cam ring 5 has a main cam surface 11 and a sub-cam surface 12 which are cam surfaces of different shapes provided at positions diametrically opposed to each other. Pump chamber 10 defined by surface 11
And a sub-pump section 14 having a pump chamber 10 defined by the sub-cam surface 12. Then, the maximum volume of the pump chamber 10 of the sub pump section 14 is made larger than the maximum volume of the pump chamber 10 of the main pump section 13. Further, the cam ring 5 is provided with a main suction port 15 and a sub suction port 16, and a main discharge port 17 and a sub discharge port 18, respectively, on both side surfaces thereof. The main suction port 15 and the main discharge port 17 communicate with the main pump section 13 and the sub suction port 16
The sub discharge port 18 communicates with the sub pump section 14.

The cover is provided with an inlet port communicating with a reservoir for storing hydraulic oil, and the main suction port 15 and the sub suction port 16 communicate with the inlet port. Here, a filter is provided between the reservoir and the inlet port for capturing foreign matter mixed in the hydraulic oil and cleaning the hydraulic oil.

On the other hand, the body 2 is provided with a main discharge passage 19 composed of a groove covered by the seal plate and a sub discharge passage 22 composed of a first sub discharge passage 20 and a second sub discharge passage 21. . One end of the main discharge passage 19 is
The other end communicates with the main discharge port 17 and the other end communicates with an outlet port 23 which communicates with a working oil passage to the continuously variable transmission. Also, the first
One end of the sub discharge passage 20 communicates with the sub discharge port 18,
The other end communicates with the inflow port 35 of the switching valve 30 described later,
One end of the sub discharge passage 21 communicates with the outflow port 36 of the switching valve 30, and the other end communicates with the outlet port 23.

Further, the body 2 is provided with a switching valve 30 composed of a spool valve, and the switching valve 30 communicates and shuts off the sub-discharge passage 22 with the main discharge passage 19 so that the sub-pump portion 14 The supply of the hydraulic oil discharged from the pump chamber 10 to the continuously variable transmission is controlled.

Specifically, the switching valve 30 is slidable in the direction of the axis L in a valve body formed by a part of the body 2 and a valve hole 31 provided in the body 2 (valve body). And a return spring 33 composed of a compression spring disposed between the spool 32 and the body 2. The body 2 has a control port 34, an inflow port 35, an outflow port 36, and a return port 37, each of which is formed of an annular groove.
Are provided, and the ports 34 to 37 intersect with the valve hole 31. The spool 32 includes a first land 38 and a second land 39 having outer peripheral surfaces 40 and 41, each having a circular cross section in a cross section orthogonal to the axis L of the spool 32;
An annular groove 42 is provided between 38 and 39. At this time, between the outer peripheral surfaces 40 and 41 of the spool 32 and the peripheral wall surface 31a of the valve hole 31, in order to supply a minimum amount of hydraulic oil required for lubrication of a sliding portion formed by those surfaces, A minimal radial gap is provided to allow hydraulic fluid leakage.

A control oil whose hydraulic pressure is controlled in accordance with the engine speed of the internal combustion engine is supplied to the control port 34 via a control passage (not shown) provided in the body 2.
At one end of the spool 32, there is provided a pressure receiving surface 32a which faces the control port 34 and receives the oil pressure of the control oil, and at the other end, a spring chamber having a bottomed circular hole for accommodating the return spring 33. 32b is provided. Further, since the return port 37 communicates with the inlet port via a return passage (not shown) provided in the cover, the return port 37 is an outflow port different from the outflow port 36. . Note that 43
Is a relief valve.

Next, the spool 32 and each of the ports 34 to 37 will be further described with reference to FIG. Annular groove 42
Are connected to the bottom wall surface 44, the bottom wall surface 44 on the side in the axis L direction, and the curved surfaces 45, 46; The first side wall surface 47 and the second side wall surface 48 are formed. The first and second side wall surfaces 47 and 48 are formed on the outer peripheral surfaces 40 and 41 of the adjacent first and second lands 38 and 39, respectively, in the axial section of the body 2 and the spool 32 that is the section including the axis L. Between 41 and 1
Make an angle γ of 35 °.

Further, the first and second side walls 47 and 48 and the first and second lands 3 adjacent to the side walls 47 and 48, respectively.
8 and 39 are connected to the outer peripheral surfaces 40 and 41 by first and second tapered surfaces 49 and 50 as inclined surfaces which are a part of a conical surface provided over the entire circumference of the spool 32, respectively. Each outer peripheral surface
The first edges 51, 52 are formed by 40, 41 and the respective tapered surfaces 49, 50.
Is formed. The first and second tapered surfaces 49 and 50 have an obtuse angle of more than 135 ° with respect to the outer peripheral surfaces 40 and 41 of the corresponding first and second lands 38 and 39 in the axial section, respectively, at 160 °. Make an angle α. Therefore, each outer peripheral surface 4
The angle α of the first edges 51, 52 formed by the intersection of the tapered surfaces 49, 50 with 0, 41 is 160 °, and the angle α of the first edges 51, 52 is A second edge 53, formed by the intersection of the taper surfaces 49, 50 with the second edge 53,
It is larger than the angle β of 54.

Thus, the angle β between the second edges 53 and 54
Is smaller than the angle α of the first edges 51, 52, the first and second side wall surfaces 47, 48 despite the fact that the angle α of the first edges 51, 52 is an obtuse angle larger than 135 °. Can be steeply inclined, and the flow path cross-sectional area in the annular groove 42 can be increased.

On the other hand, the inflow port 35 provided in the body 2
The first and second side wall surfaces 55 and 56 in the direction of the axis L and the valve hole 31;
Has a first edge 57 and a second edge 58 of the inflow port 35 respectively formed by intersecting with the peripheral wall surface 31a,
Similarly, the outflow port 36 has a first edge 61 and a second edge 62 of the outflow port 36 formed by the intersection of the first and second side wall surfaces 59 and 60 in the direction of the axis L and the peripheral wall surface 31a.
Further, the reflux port 37 is provided with a first edge 65 and a second edge of the reflux port 37 formed by the intersection of the first and second side wall surfaces 63 and 64 in the direction of the axis L and the peripheral wall surface 31a. Has 66.

In the switching valve 30 having such a structure, when the engine speed is equal to or lower than a predetermined value in the low engine speed range, the control port
Since low hydraulic control oil is supplied to the spool 34, the spool 32
By the elastic force of the return spring 33, the inflow port 35 and the outflow port 36 communicate with each other via the annular groove 42, and the return port 37 occupies the first position closed by the second land 39. In this first position, shown in solid lines in FIG. 2, the first edge 51 of the spool 32 occupies the same position in the direction of the axis L as the first edge 61 of the outflow port 36 and likewise the first edge of the spool 32
52 occupies the same position as the second edge 58 of the inflow port 35 in the direction of the axis L.

Referring also to FIG. 1, the hydraulic oil sucked through the inlet port is supplied to the main suction port.
It is sucked into the pump chamber 10 from the sub suction port 15 and the sub suction port 16 respectively, and is discharged to the main discharge port 17 and the sub discharge port 18. The hydraulic oil discharged to the main discharge port 17 reaches the outlet port 23 via the main discharge passage 19 as shown by an arrow in FIG. 2, and is supplied from the outlet port 23 to the hydraulic oil passage. The hydraulic oil discharged to the sub-discharge port 18 reaches the inflow port 35 of the switching valve 30 through the first sub-discharge passage 20 as shown by an arrow in FIG. Through the outflow port 36 which flows through the second sub-discharge passage 21 and reaches the outlet port 23, it joins with the hydraulic oil from the main discharge passage 19 and is supplied to the hydraulic oil passage. As described above, when the engine speed is equal to or lower than the predetermined value, the working oil passage is provided with the sum of the main discharge flow rate from the main pump section 13 and the sub discharge flow rate larger than the main discharge flow rate from the sub pump section 14. A quantity of hydraulic oil is supplied.

When the engine speed exceeds the predetermined value, high-pressure control oil is supplied to the control port 34, so that the spool 32 moves in the direction of the axis L against the elastic force of the return spring 33. The inflow port 35 and the return port 37 communicate with each other through the annular groove 42, and the outflow port 36 occupies the second position closed by the first land 38. In this second position, shown in phantom in FIG.
The edge 51 is the same axis L as the first edge 57 of the inflow port 35
The first edge 52 of the spool 32 occupies the same position in the direction of the axis L as the second edge 66 of the return port 37.

At this time, of the hydraulic oil sucked into the pump chamber 10 from the main suction port 15 and the sub suction port 16, the hydraulic oil discharged from the main discharge port 17 passes through the main discharge passage 19 to the outlet port 23. Reached, exit port 23
From the sub-discharge port 18, the hydraulic oil discharged from the sub-discharge port 18 reaches the inflow port 35 of the switching valve 30 via the first sub-discharge passage 20, and further flows through the annular groove 42. Through the reflux port 37 which communicates with the inlet port, the fluid returns to the inlet port through the reflux passage. Thus, when the engine speed exceeds the predetermined value, the port communicating with the inflow port 35 is switched from the outflow port 36 to the recirculation port 37, and the main oil from the main pump unit 13 is connected to the working oil passage. Hydraulic oil at the discharge flow rate is supplied.

As described above, when the engine speed exceeds the predetermined value, the spool 32 moves in the direction of the axis L to cut off the communication between the inflow port 35 and the outflow port 36 and moves out of the outflow port 36. The state when the spool 32 approaches the imaginary circle C immediately before occupying the second position where the spool 32 is closed by the first land 38 will be described with reference to FIG.

When the spool 32 moves in the direction of the axis L, the first
Outflow port that forms a narrowed flow path with tapered surface 49
Approaching the second edge 62 of 36, in the axial section,
Until the first tapered surface 49 comes into contact with the imaginary circle C at the contact point P, foreign matter in the hydraulic oil flows from the annular groove 42 through the narrowed flow path to the outflow port 36. It is not pinched between the first tapered surface 49 and the second edge 62 or the peripheral wall surface 31a.
Is not sandwiched in the direction of the axis L.

Then, the spool 32 further moves to the second edge 62
Moving closer to the first tapered surface in the axial section.
Reference numeral 49 denotes an imaginary circle C centered on the second edge 62, which is in contact with the imaginary circle C having a radius equal to the maximum diameter of the foreign matter not captured by the filter (see the two-dot chain line in FIG. 3).
(See the solid line in FIG. 3). At this time, for example, when the foreign matter 70 having the maximum diameter mixed in the hydraulic oil flowing out from the annular groove 42 to the outflow port 36 tries to pass through the narrowed flow path, the foreign matter is reduced to the first in the axial cross section. The spool 32 and the second edge 62 or the peripheral wall surface 31a are located at a position upstream of the portion of the minimum flow path cross-sectional area formed between the contact point P of the tapered surface 49 and the virtual circle C and the second edge 62. It can happen that it is sandwiched between.

When the foreign matter 70 is caught, the outer peripheral surface 40
The angle α between the first tapered surface 49 and the first tapered surface 49 is an obtuse angle larger than 135 °, and therefore, the contact position between the foreign material 70 and the first tapered surface 49, that is, the contact position between the foreign material 70 and the spool 32, The position is further away from the second edge 62 or the peripheral wall surface 31a in the radial direction of the valve hole 32 and closer to the second edge 62 in the direction of the axis L. As a result, a part of the foreign matter 70
The degree of protrusion into the inside 36 becomes smaller or no longer, and foreign matter is less likely to be pinched between the spool 32 and the outflow port 36 in the direction of the axis L. In addition, due to the first tapered surface 49, when the spool 32 further approaches the second edge 62, of the force of the spool 32 pressing the foreign matter 70 toward the body 2, the foreign matter 70 is pressed in the direction of the axis L. The component force is reduced, and at this point, the foreign matter 70 is less likely to be caught between the spool 32 and the outflow port 36 in the direction of the axis L.

Thereafter, the spool 32 is further moved to the second edge 62
, The foreign matter having a diameter smaller than that of the foreign matter 70 having the largest diameter is treated in the same manner as the foreign matter 70 having the largest diameter described above, with the first tapered surface 49 and the second edge 62 or the peripheral wall surface 31.
There is a possibility that a foreign object may be caught between the first and second a, but even if the foreign object is caught, the diameter of the foreign object itself is small, and the contact position between the first tapered surface 49 and the foreign object further increases in the direction of the axis L. Since the second edge 62 is closer to or closer to the inflow port 35 than the second edge 62, the foreign matter is less likely to be caught in the direction of the axis L between the first tapered surface 49 and the outflow port 36. Then, the spool 32 further moves, and the second
Occupy position.

When the spool 32 moves from the second position to the first position, the spool 32 moves to the second tapered surface 50.
When approaching the first edge 65 of the return port 37 that forms a narrowed flow path between the spool 32 and the return port 37, the foreign matter passing through the narrowed flow path is moved between the spool 32 and the return port 37. A phenomenon similar to that occurring between the spool 32 and the outflow port 36 occurs, and foreign matter is less likely to be caught between the spool 32 and the return port 37 in the direction of the axis L.

The outer peripheral surfaces 40 and 41 of the spool 32 and the valve hole 31
The peripheral wall 31a, the force acting on the spool 32 based on the hydraulic pressure of the hydraulic oil at each of the inflow port 35, the outflow port 36, and the recirculation port 37 is not uniform. Then, the spool 32 is inclined with respect to the direction of the axis L. When the spool 32 moves from the first position to the second position or in the second position, When moving to the first position, the spool 32 moves to the second edge 62 of the outflow port 36 or the return port 37.
Approaching the first edge 65 of the spool 32 and the second edge 62
Or, even if the first edge 65 abuts, the second edge
Since the 62 or the first edge 65 contacts the first tapered surface 49 or the second tapered surface 50 whose obtuse angle with the outer peripheral surface 40 or the outer peripheral surface 41 is greater than 135 °, the spool 32
Is smoothly guided by the first and second tapered surfaces 49 and 50 having inclination angles closer to parallel to the direction of the axis L without being caught by the edges 62 and 65.

Hereinafter, the effects of the embodiment configured as described above will be described. When the spool 32 moves from the first position to the second position, when the hydraulic oil from the inflow port 35 flows out through the annular groove 42 to the outflow port 36, and when the spool 32 moves from the second position to the second position, When moving to the first position, when hydraulic oil from the inflow port 35 flows out to the return port 37 through the annular groove 42, foreign matter in the hydraulic oil is removed from the spool 32.
Even if the foreign matter is sandwiched between the tapered surfaces 49, 50 of the second port 62 and the second edge 62 of the outflow port 36, the first edge 65 of the return port 37, or the peripheral wall surface 31a, the foreign matter is not removed.
The degree of protrusion of the foreign matter protruding into the inside 37 becomes small or no longer protrudes, and the component force for pressing the sandwiched foreign matter in the direction of the axis L also becomes small. Therefore, the foreign matter in the direction of the axis L between the spool 32 and the port is reduced. Becomes less likely to be caught, and the frequency with which the spool 32 cannot move is reduced, and the occurrence of locking of the switching valve 30 can be suppressed. At this time, it is not necessary to increase the gap between the outer peripheral surfaces 40 and 41 of the first and second lands 38 and 39 of the spool 32 and the peripheral wall surface 31a of the valve hole 31. The leakage of hydraulic oil between the inflow port 35 and the return port 37 does not increase.

Due to the gap between the outer peripheral surfaces 40 and 41 of the spool 32 and the peripheral wall surface 31a of the valve hole 31, even if the spool 32 is inclined with respect to the direction of the axis L, the inclined state is maintained. Even if the spool 32 approaches the second edge 62 or the first edge 65 and the spool 32 contacts the edges 62 and 65, the second edge 62 or the first edge 65 is
Alternatively, the spool 32 abuts on the first tapered surface 49 or the second tapered surface 50 whose obtuse angle with the outer peripheral surface 41 is greater than 135 °, so that the spool 32 is not caught by the edges 62 and 65 and the first and second taper surfaces are not caught. The guide is smoothly guided by the two tapered surfaces 49 and 50, so that the movement of the spool 32 is smooth and the switching between the outflow port 36 and the return port 37 is quickly performed.

The inclined surface has a single first and second tapered surface 49, 50.
Therefore, the processing for forming the inclined surface is facilitated, the cost of the switching valve 30 can be reduced, and the angle β of the second edges 53 and 54 is changed to the angle α of the first edges 51 and 52. Since the first and second side walls 47 and 48 are formed to be steeply inclined, the cross-sectional area of the passage in the annular groove 42 can be increased, and the hydraulic oil flowing from the inflow port 35 It is easy to secure the flow rate in the annular groove 42, and the switching valve 30 can be applied to an oil passage through which a large flow of hydraulic oil flows, and the applicable range of the switching valve 30 is widened.

Hereinafter, an embodiment in which a part of the configuration of the above embodiment is changed will be described with respect to the changed configuration. In the above-described embodiment, the first and second side walls 47 and 48 are formed along the outer peripheral surfaces 40 and the corresponding first and second lands 38 and 39 on the axis L section.
At an angle of 135 ° each with 41, 13
The angle may be other than 5 °, for example, 90 ° or more. The first and second tapered surfaces 49 and 50 are
In the axial cross section, the corresponding first and second lands 38,
Although an angle of 160 ° was formed between the outer peripheral surfaces 40 and 41 of 39, the angle may be larger than 135 °, and the first and second tapered surfaces 49 and 50 are not captured by the length in the direction of the axis L or the filter. It is set appropriately depending on the maximum diameter of the foreign matter.

The inclined surface may be a multi-stage tapered surface having a plurality of tapered surfaces, or may be a spindle-shaped surface convex outward in the radial direction. When the inclined surface is a spindle-shaped surface, the angle formed between the inclined surface and the outer peripheral surface of the land is the angle formed between the tangent of the spindle-shaped surface and the outer peripheral surface of the land in the axial cross section. It is.

When the spool 32 moves, the port in which the flow path narrowed by the inclined surface is formed may be an inflow port. In the above embodiment, the valve body of the switching valve 30 is provided integrally with the body 2 of the vane pump 1.
The switching valve may be separate from the body 2, in which case the spool may be further fixed and the valve body may be moved.

The vane pump 1 supplies hydraulic oil to the continuously variable transmission. However, the vane pump 1 may be a fluid utilization device using hydraulic oil or a fluid other than the continuously variable transmission. It does not have to be mounted. further,
The vane pump 1 can be driven by a drive source other than the internal combustion engine.

[Brief description of the drawings]

FIG. 1 is a plan view of a vane pump according to an embodiment of the present invention as viewed from a mating surface of a body, and a sectional view of a spool of a switching valve.

FIG. 2 is a partially enlarged view of a switching valve.

FIG. 3 is an explanatory diagram when a spool of a switching valve sandwiches foreign matter.

FIG. 4 is a diagram illustrating a control valve of the related art and an operation state thereof.

FIG. 5 is an explanatory diagram when a foreign matter is interposed between valve elements of a control valve.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Vane pump, 2 ... Body (valve body), 3 ... Pump unit, 4 ... Drive shaft, 5 ... Cam ring, 6 ... Rotor, 7 ... Vane groove, 8 ... Vane, 9 ... Cam surface, 10 ... Pump chamber, 11 … Main cam surface, 12… Sub cam surface, 13… Main pump part, 14… Sub pump part, 15… Main suction port,
16 ... Sub suction port, 17 ... Main discharge port, 18 ... Sub discharge port, 19 ... Main discharge passage, 20 ... First sub discharge passage, 21 ... Second sub discharge passage, 22 ... Sub discharge passage, 23 ... Exit port , 30 ... switching valve, 31 ... valve hole, 31a ... peripheral wall surface, 32 ...
Spool, 33 return spring, 34 control port, 35 inflow port, 36 outflow port, 37 reflux port, 38, 39 land, 40, 41 outer peripheral surface, 42 annular groove, 43 relief valve, 44
... bottom wall, 45, 46 ... curved surface, 47, 48 ... side wall surface, 49, 50 ...
Tapered surface, 51 ... first edge, 53, 54 ... second edge, 55,
56 ... side wall surface, 57, 58 ... edge, 59, 60 ... side wall surface, 61, 62
... edge, 63, 64 ... side wall surface, 65, 66 ... edge, 70 ... foreign matter, C ... virtual circle, L ... axis, P ... contact point.

Claims (2)

[Claims] A valve body provided with an inflow port and an outflow port respectively communicating with a valve hole and a plurality of oil passages for hydraulic oil; and a pair of lands slidably fitted in the valve hole. A spool having one annular groove provided therebetween, and the spool relatively moves in the valve hole in the axial direction with respect to the valve hole, whereby the outflow port passes through the annular groove. A switching valve which is in communication with the inflow port and which is shut off from the inflow port by any of the lands, wherein a side wall surface of the annular groove and an outer peripheral surface of the land adjacent to the side wall surface are formed through an inclined surface. The inclined surface forms an obtuse angle of more than 135 ° with the outer peripheral surface in an axial cross section passing through the axis of the valve body and the spool, and the relative movement of the spool. Sometimes A position in contact with an imaginary circle whose radius is the maximum diameter of the foreign matter mixed in the hydraulic oil around the edge of the outflow port or the inflow port forming a narrowed flow path between the inclined surface and the inflow port. Switching valve characterized by being able to occupy. 2. The method according to claim 1, wherein the inclined surface has a single tapered surface,
2. The switching device according to claim 1, wherein an angle of a second edge formed by the tapered surface and the side wall surface is smaller than an angle of a first edge formed by the tapered surface and the outer peripheral surface. valve.