JP4258194B2 - Hydraulic control valve and hydraulic control device for automatic transmission - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to, for example, a hydraulic control valve used for hydraulic control of an automatic transmission of a vehicle and a hydraulic control device of the automatic transmission.
[0002]
[Prior art]
For example, in hydraulic control of an automatic transmission of a vehicle, when a clutch is shifted from a non-engaged state to an engaged state, a corresponding flow rate of oil is supplied to the clutch side in order to shorten the operation time. However, in the engaged state (half-clutch state and fully engaged state), a very small amount of oil is supplied. The hydraulic control valve is desired to stably control the hydraulic pressure without depending on such a change in the supply flow rate to the clutch.
[0003]
The hydraulic control valve is usually formed with a cylindrical valve body formed with a plurality of ports, and a land portion that is slidably provided in the valve body and has an outer peripheral surface that is in sliding contact with the inner peripheral surface of the valve body. And a spool valve. Then, the opening area of the port is changed on the outer peripheral surface according to the sliding position of the spool valve with respect to the valve body. As a result, the hydraulic pressure and flow rate of the hydraulic chamber of the clutch are controlled. For example, when the outer peripheral surface of the land portion fully closes the port (line port) to which oil is supplied into the hydraulic control valve, the oil supply flow rate to the clutch side is almost zero, but the spool valve When the end face of the land portion passes over the line port and the line port is opened by sliding, the supply flow rate to the clutch side increases. The hydraulic control valve generally has a phenomenon that the supply flow rate rapidly increases at the moment when the line port opens, that is, at the moment when the end face of the land portion is applied to the line port. As a result, there is a problem that it is difficult to control the hydraulic pressure at a minute flow rate in the engaged state of the clutch.
[0004]
Therefore, in the hydraulic control valve, a configuration in which a notch is formed at an edge of the land portion (a portion where the outer peripheral surface and the end surface of the land portion intersect) has been conventionally employed. FIG. 10 shows the relationship between the supply flow rate to the clutch side (hereinafter referred to as flow rate gradient) and the stroke amount the spool valve has moved relative to the valve body when the notch is formed. In FIG. 10, the leak region is a region where the spool valve moves while the outer peripheral surface of the land portion fully closes the line port, and the notch region is the region where the spool valve moves while the end surface of the notch passes over the line port. The area and land area are areas where the spool valve moves while the end face of the land portion passes over the line port.
[0005]
As is clear from FIG. 10, there is a large difference between the flow rate gradients in the leak region, the notch region, and the land region, and they are not configured to be smoothly connected. Therefore, even if a configuration with a notch is adopted, it is still difficult to suppress a change in flow rate particularly when shifting from the leak region to the notch region.
[0006]
As a means for solving such a problem, a configuration in which a plurality of notches are provided and the lengths of each notch from the end surface of the land to the spool valve sliding direction are set differently, and the notches are formed in a predetermined shape. The structure to do is also a well-known technique (for example, refer patent document 1). However, with this technique, it is difficult to form a plurality of notches, and the accuracy of setting the length of each notch to a predetermined length and the accuracy of making the notch into a predetermined shape are required. was there.
[0007]
[Patent Document 1]
JP-A-10-252903 (page 2-5, FIG. 1-16)
[0008]
[Problems to be solved by the invention]
It is a technical object of the present invention to make a hydraulic control valve easy to form and smooth a flow rate change with respect to a stroke amount of a spool valve.
[0009]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the technical means taken in the present invention includes a cylindrical valve body having a plurality of ports formed on a peripheral wall, and a slidably provided in the valve body. A spool valve formed with a land portion having an outer peripheral surface in sliding contact with the inner peripheral surface, and an opening area of the port is changed on the outer peripheral surface in accordance with a sliding position of the spool valve with respect to the valve body. A hydraulic control valve for controlling a hydraulic pressure supplied to a type, and is formed on the outer peripheral surface, and has a predetermined width in a sliding direction of the spool valve from an end surface of the land portion and has a predetermined width between the inner peripheral surface and the inner peripheral surface. It is set as the structure provided with the step part which comprises a clearance gap.
[0010]
In this configuration, when the spool valve slides with respect to the valve body, the spool valve starts from the region where the land portion fully closes the port (leak region), and the step portion of the land portion first passes over the port. Transition to a region (step region) to be performed, and further to a region (land region) where the end face of the land portion passes over the port. In the stepped region, a predetermined gap is formed between the inner peripheral surface of the valve body, and oil flows through this gap. At this time, if this gap is set very small, the change in the oil flow rate gradient when shifting from the leak region to the stepped region can be made very small. Therefore, the flow rate change with respect to the stroke amount of the spool valve can be made smooth.
[0011]
Furthermore, in this case, if the circumferential size of the stepped portion is set large, for example, over the entire circumference, the flow rate in the stepped region follows the flow characteristics of the viscous fluid in the so-called annular gap. The gradient can be increased smoothly with a small stroke amount. As a result, when the transition from the step region to the land region is made, the difference in the flow rate gradient is set to be small, so that the flow rate change at that time becomes smooth.
[0012]
And since this step part needs only to form in an outer peripheral surface so that it may have predetermined width from the end surface of a land part, the formation is easy.
[0013]
Preferably, a notch formed in the stepped portion and notched in the moving direction of the spool valve from the end surface is provided.
[0014]
In this configuration, a region (notch region) in which the spool valve moves while the notch passes over the port is set between the step region and the land region. Since the flow rate gradient in the notch region is a value between the flow rate gradients in the step region and the land region, the flow rate change with respect to the stroke amount of the spool valve becomes smoother.
[0015]
Further, a friction engagement element composed of a driving side rotating body and a driven side rotating body, and the driving side rotating body and the driven rotating body are brought into contact with one of the driving rotating body side and the driven rotating body by pressing force. A piston that can be engaged, a hydraulic chamber that is partitioned from the friction engagement element by the piston, and that changes a pressing force to the piston in accordance with a hydraulic pressure that is supplied, and a hydraulic pressure that is supplied to the hydraulic chamber is controlled A hydraulic control device for an automatic transmission that includes a hydraulic control mechanism and switches the gear position by engaging or disengaging the driving side rotating body and the driven side rotating body, wherein the hydraulic control mechanism includes a peripheral wall A cylindrical valve body having a plurality of ports formed therein, and a spool valve provided in the valve body so as to be slidable and having a land portion having an outer peripheral surface slidably contacting the inner peripheral surface of the valve body; , Shaped on the outer peripheral surface A step portion that has a predetermined width in the sliding direction of the spool valve from the end surface of the land portion and forms a predetermined gap with the inner peripheral surface, according to the sliding position of the spool valve. Provided with a hydraulic control valve that controls the hydraulic pressure supplied to the hydraulic chamber by changing the opening area of the port on the outer peripheral surface, and the communication path that is formed in the piston and discharges oil to the outside of the hydraulic chamber is choked. good.
[0016]
In this automatic transmission hydraulic control device, since the hydraulic control valve uses the flow of the gap between the stepped portion and the inner peripheral surface, the change in the passage flow rate due to the temperature change becomes large. That is, the viscosity of the oil increases at low temperatures, and as a result, the flow rate flowing through the gap decreases. Here, by choking the communication path that discharges the oil to the outside of the hydraulic chamber, the required amount of oil to be supplied to the hydraulic chamber at a low temperature can be reduced, and the influence of a decrease in the flow rate of the gap can be reduced. . 1
[0017]
DETAILED DESCRIPTION OF THE INVENTION
(First Embodiment) A first embodiment of the present invention will be described with reference to the accompanying drawings. In each figure, a valve body 20, a half of a spool valve 21, a piston 12, a driving side rotating body 11a, a driven side rotating body 11b and a hydraulic chamber 13 shown in FIG.
[0018]
1 to 3 are schematic views showing the configuration of a hydraulic control device 10 for an automatic transmission (hydraulic control device for an automatic transmission). The hydraulic control device 10 of the automatic transmission includes a clutch device 11 (friction engagement element) including a driving side rotating body 11a (driving side rotating body) and a driven side rotating body 11b (driven side rotating body), and a pressing force. A piston 12 (piston) (shown in FIG. 2) that can contact the driving side rotating body 11a and engage the driving side rotating body 11a and the driven side rotating body 11b, and is separated from the clutch device 11 by the piston 12 and supplied. A hydraulic chamber 13 (hydraulic chamber) that changes the pressing force to the piston 12 in accordance with the hydraulic pressure, a hydraulic control mechanism 80 (hydraulic control mechanism) that controls the hydraulic pressure supplied to the hydraulic chamber 13, and the like are provided. Then, the drive side rotator 11a and the driven side rotator 11b are engaged or disengaged to switch the gear position (not shown).
[0019]
As shown in FIG. 1, the hydraulic control mechanism 80 includes an oil pump 82 as a hydraulic source that pumps up the hydraulic oil of the strainer 90 and generates hydraulic pressure, a regulator valve 83 that adjusts the hydraulic pressure generated by the oil pump 82, A modulator valve 84 for reducing the hydraulic pressure, a linear solenoid valve 85 for adjusting the hydraulic pressure from the modulator valve 84, and a line pressure supplied from the regulator valve 83 based on the hydraulic pressure adjusted by the linear solenoid valve 85 The hydraulic chamber 13 includes a control valve 86 (hydraulic control valve) that supplies hydraulic oil, a shift valve 87 that switches an oil passage of the hydraulic oil supplied from the control valve 86, and the like. The electronic control device 81 controls the supply of hydraulic pressure to the clutch device 11 and a plurality of other clutch devices (not shown) so as to achieve a desired gear position of the automatic transmission based on the state of the vehicle.
[0020]
As shown in FIG. 3, the control valve 86 mainly includes a valve body 20 (valve body) and a spool valve 21 (spool valve) slidably provided in the valve body 20.
[0021]
The valve body 20 has a cylindrical shape, and a plurality of ports are formed on its wall 20a (peripheral wall). As the ports, a line port 20b (port) to which hydraulic oil is supplied from the regulator valve 83 side, a supply port 20c (port) for supplying hydraulic oil to the hydraulic chamber 13 via the shift valve 87, and a drain port 20d ( Port) is formed.
[0022]
Further, the spool valve 21 slides in the valve body 20 in the vertical direction shown in FIG. And three land 21a, 21b, 21c (land part) is formed in the sliding direction. The outer peripheral surface 21d (outer peripheral surface) of each land 21a, 21b, 21c is configured to be in sliding contact with the inner peripheral surface 20e (inner peripheral surface) of the valve body 20. The outer peripheral surfaces 21d of the lands 21b and 21c change the opening areas of the line port 20b, the supply port 20c, and the drain port 20d according to the sliding position of the spool valve 21 with respect to the valve body 20. As a result, the hydraulic pressure of the hydraulic oil supplied to the hydraulic chamber 13 is controlled. The sliding position of the spool valve 21 relative to the valve body 20 is controlled by a solenoid and a spring (not shown) and the hydraulic pressure in the valve body 20.
[0023]
Next, step portions 21e and 21f (step portions) formed on the lands 21a and 21b will be described. The outer peripheral surface 21d of the land 21a has a predetermined width w from the lower end surface 21g (end surface) in FIG. 3 to the upper direction in FIG. 3, which is the sliding direction of the spool valve 21, and between the inner peripheral surface 20e and the land 21a. A stepped portion 21e that forms a predetermined gap d is formed. The step 21e is formed over the entire circumferential direction (the entire circumference) of the outer peripheral surface 21d of the land 21a. In this embodiment, the step portion 21e is obtained by polishing and processing the entire circumference of the outer peripheral surface 21d, and is very easy to form. Similarly, the outer peripheral surface 21d of the land 21b has a predetermined width w from the upper end surface 21h (end surface) in FIG. 3 to the lower direction in FIG. 3, which is the sliding direction of the spool valve 21, and the inner peripheral surface 20e. A step portion 21f forming a predetermined gap d is formed between them. The step portion 21f is also obtained by polishing and processing the entire circumference of the outer peripheral surface 21d of the land 21b, and is very easy to form. In the present embodiment, the widths w and the gaps d of the step portions 21e and 21f are the same, but are not limited to the same.
[0024]
The stepped portion 21e is formed with a notch 21i (notch) that is notched from the end surface 21g in the upward direction of FIG. The notch 21i is formed at a predetermined location in the circumferential direction of the step portion 21e. Similarly, a notch 21j (notch) is formed in the stepped portion 21b. The notch 21j is notched downward from the end surface 21h in FIG. The notch 21j is also formed at a predetermined location in the circumferential direction of the step portion 21f.
[0025]
Next, the piston 12 will be described. As shown in FIG. 2, the piston 12 is formed with a communication path 12 a (communication path) that discharges hydraulic oil from the hydraulic chamber 13 to the clutch 11 side. The communication path 12a is choked. Therefore, when the hydraulic pressure is constant, the flow rate of the hydraulic oil is different from the orifice shape in which the flow rate of the hydraulic oil does not depend on the viscosity. For example, when the temperature of the hydraulic oil is low, the viscosity increases and the flow rate decreases.
[0026]
Here, the operation of the hydraulic control device 10 of the automatic transmission according to the present embodiment will be described.
[0027]
When the hydraulic pressure is supplied to the hydraulic chamber 13 by the hydraulic control mechanism 80 from the non-engaged state of the clutch 11, the piston 12 moves to the clutch 11 side. As shown by the solid line in FIG. 4, in this case, in order to shorten the operation time required to switch the shift speed, a high hydraulic pressure is supplied from the shift start time t1 to t2 to quickly move the piston 12 to the clutch 11 side. . Then, from t2 to t4, a low hydraulic pressure is supplied to gradually bring the piston 12 close to the clutch 11. At time t4, the clutch 11 is in a so-called half-clutch state, and from t4 to t5, the hydraulic pressure is increased linearly to change from the half-clutch state to the complete engagement state. After t5, a predetermined hydraulic pressure is maintained in order to maintain the complete engagement state.
[0028]
The supply flow rate of hydraulic oil in this series of operations is shown in FIG. 4 (dotted line). That is, from t1 to t2, a large flow rate of hydraulic oil is supplied to supply the hydraulic pressure for moving the piston 12 as described above. Thereafter, the flow rate is linearly reduced until t3, and from t3 to t4, a standby state is maintained in which the flow rate is kept constant at a low supply flow rate. Thereafter, the flow rate is increased linearly from t4 to t5, and is maintained at a predetermined flow rate after t5. As shown in FIG. 4, in the state from t1 to t4 before the clutch 11 is engaged, the necessary flow rate before engagement required for the operation is in the range of Qb, and after t4 after the clutch 11 is engaged, The required flow rate after engagement required for the operation is in the Qa range. In particular, in a state after engagement of the clutch 11, the hydraulic oil is discharged from the communication passage 12 a of the piston 12 described above.
[0029]
Next, the operation of the control valve 86 for supplying hydraulic oil and the supply flow rate to the hydraulic chamber 13 side will be described.
[0030]
FIG. 5A shows a state in which the outer peripheral surface 21d of the land 21b fully closes the line port 20b. In this state, the supply port 20c and the drain port 20d are open, and the flow rate to the hydraulic chamber 13 side is almost zero. The sliding area of the spool valve 21 in this state is referred to as a leak area (shown in FIG. 6). When the spool valve 21 slides downward in FIG. 5 from this state, as shown in FIG. 5b, the spool valve 21 slides while the step portion 21f passes over the line port 20b. The sliding area of the spool valve 21 in this state is referred to as a step area (shown in FIG. 6). In this region, hydraulic fluid flows from the line port 20b into the valve body 20 via the gap d. Further, when the spool valve 21 slides downward in FIG. 5, as shown in FIG. 5c, the spool valve 21 slides while the notch 21j passes over the spool valve 20b. The sliding area of the spool valve 21 in this state is referred to as a notch area (shown in FIG. 6). In this region, the discharge of the hydraulic oil from the drain port 20d is stopped by the land 21a. Further, when the spool valve 21 moves downward, although not shown, the spool valve slides while the end face 21h of the land 21b passes over the line port 20b. The sliding area of the spool valve 21 in this state is referred to as a land area.
[0031]
FIG. 6 shows the relationship between the sliding stroke (horizontal axis) of the spool valve 21 from the leak region to the notch region and the supply flow rate (vertical axis) to the hydraulic chamber 13 side. As described above, the hydraulic oil flows through the gap d in the stepped region, but in the present embodiment, the gap d is set to be very small, so when the transition from the leak region to the stepped region, There is almost no change in the flow rate gradient (the amount of change in the flow rate with respect to the stroke amount of the spool valve 21). That is, the change in the flow rate with respect to the stroke amount of the spool valve 21 is smooth.
[0032]
Furthermore, in the stepped region, the stepped portion 21f is formed over the entire circumference of the outer peripheral surface 21d, so that the flow rate change follows the characteristics of the viscous fluid in the so-called annular gap. That is, the flow rate is inversely proportional to the overlapping amount L (shown in FIG. 3) of the outer peripheral surface 21d of the land 21b and the inner peripheral surface 20e of the valve body 20. As a result, the flow rate gradient can be increased smoothly with a small stroke amount. As a result, the difference in flow rate gradient is small when shifting from the step region to the notch region. As shown in FIG. 6, the flow rate Qt at the transition point from the step region to the notch region is outside the range of the required flow rate Qa after engagement. Therefore, the flow rate can be smoothly changed even in the control at a minute flow rate after the clutch 11 is engaged. The hydraulic control by the control valve 86 is also stable.
[0033]
FIG. 7 shows the characteristic of the influence of the temperature change in the relationship between the stroke amount of the spool valve 21 and the flow rate. As shown in FIG. 7, the control valve 86 according to the present embodiment uses a flow of a minute gap d in the step region, and thus has a large influence on the flow rate due to temperature. That is, when the viscosity increases due to a decrease in the temperature of the hydraulic oil, the flow rate in the same stroke amount decreases (shift from the dotted line characteristic to the solid line characteristic in FIG. 7). As a result, the flow rate Qt at the transition point from the step region to the notch region is also reduced. Here, as described above, the communication path 12a of the piston 12 is choked, and the flow rate of the communication path 12a is reduced when the viscosity of the hydraulic oil is decreased due to a decrease in the temperature of the hydraulic oil. Therefore, when the temperature of the hydraulic oil is lowered, the range of the required flow rate Qa after engagement is also reduced (shifted from the one-dot chain line in FIG. 7 to the two-dot chain line in FIG. 7). As described above, even when the flow rate Qt at the transition point decreases due to the decrease in the temperature of the hydraulic oil, the flow rate Qt does not fall within the range of the required flow rate Qa after the engagement, and the hydraulic chamber 13 of the control valve 86. The flow rate to the side and the temperature control on the hydraulic control are not affected.
[0034]
As for the step 21e of the land 21a, when the state of FIG. 5c is changed to the state of FIG. 5b, the hydraulic oil flows to the drain port 20d through the gap d of the step 21e. Therefore, the flow rate change at that time is smooth.
[0035]
In the present embodiment, the step portions 21e and 21f are formed over the entire circumference of the outer peripheral surface 21d. However, the configuration is not limited to the entire circumference. In other words, the circumferential size of the stepped region may be formed so that the flow rate characteristic in the stepped region follows the above-described viscous fluid characteristic in the annular gap. In the present embodiment, the formation over the entire circumference facilitates the formation.
[0036]
(Second Embodiment) FIG. 8 shows a second embodiment. As shown in FIG. 8, the spool valve 21 of the present embodiment has a configuration without the notches 21i and 21j. In this configuration, a transition is made from the stepped region to the land region (without going through the notch region). The flow rate gradient in the land region is larger than the flow rate gradient in the notch region of the first embodiment. For example, is the width w of the stepped portions 21e and 21f set larger than that of the first embodiment? By adopting a configuration in which the gap d is changed according to the width w, the flow rate gradient immediately before the transition from the stepped region to the notch region can be brought close to the flow rate gradient immediately after the land region shift. By doing so, it is possible to smooth the flow rate change during the transition from the step region to the land region.
[0037]
(Third Embodiment) FIG. 9 shows a third embodiment. As shown in FIG. 9, in this embodiment, the notches 20f and 20g are notched in the opening portions of the line port 20b and the drain port 20d of the wall 20a of the valve body 20. Even in such a configuration, the flow rate change can be smoothly controlled by the step portions 21e and 21f, and the control of the flow rate and the hydraulic pressure becomes stable. Further, the notch may be formed in the opening portion of the supply port 20c.
[0038]
【The invention's effect】
In the present invention, the change in the oil flow rate gradient when shifting from the leak region to the stepped region can be made extremely small. Therefore, the flow rate change with respect to the stroke amount of the spool valve can be made smooth. In addition, if the size of the stepped portion in the circumferential direction is large, for example, it is set so as to extend over the entire circumference, the flow rate in the stepped region follows the flow rate characteristics of the viscous fluid in the so-called annular gap, so the flow rate gradient is It can be increased smoothly with a small stroke amount. Further, since the step portion only needs to be formed on the outer peripheral surface so as to have a predetermined width from the end surface of the land portion, the formation thereof is easy.
[0039]
In the present invention, if the notch region is set, the flow rate gradient of the notch region is a value between the flow rate gradient of the step region and the land region, so the flow rate change with respect to the stroke amount of the spool valve is smoother. It becomes.
[0040]
In the present invention, the communication path for discharging oil to the outside of the hydraulic chamber is choked to reduce the required amount of oil to be supplied to the hydraulic chamber at a low temperature, and to reduce the influence of a decrease in the flow rate of the gap. it can.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a hydraulic control device for an automatic transmission according to a first embodiment.
FIG. 2 is a diagram showing a configuration from a control valve to a clutch of a hydraulic control device for an automatic transmission according to the first embodiment.
FIG. 3 is a diagram showing a control valve of the hydraulic control device for the automatic transmission according to the first embodiment.
FIG. 4 is a diagram for explaining changes in hydraulic pressure and flow rate during operation of the hydraulic control device for the automatic transmission according to the first embodiment.
FIG. 5 is a diagram illustrating an operation of a control valve of the hydraulic control device for the automatic transmission according to the first embodiment.
FIG. 6 is a diagram showing a change in flow rate due to operation of a control valve of the hydraulic control device of the automatic transmission according to the first embodiment.
FIG. 7 is a diagram illustrating the influence of temperature on the flow rate change caused by the operation of the control valve of the hydraulic control device of the automatic transmission according to the first embodiment.
FIG. 8 is a diagram showing a control valve of a hydraulic control device for an automatic transmission according to a second embodiment.
FIG. 9 is a diagram showing a control valve of a hydraulic control device for an automatic transmission according to a third embodiment.
FIG. 10 is a diagram showing a change in flow rate due to operation of a conventional hydraulic control valve.
[Explanation of symbols]
10 Hydraulic control device for automatic transmission 11 Clutch (friction engagement element)
11a Drive-side rotator 11b Driven-side rotator 12 Piston 12a Communication path 13 Hydraulic chamber 20 Valve body 20a Wall (circumferential wall)
20b Line port (port)
20c Supply port (port)
20d Drain port (port)
20e Inner peripheral surface 21 Spool valve 21a Land (land part)
21b Land (Land part)
21c Land (Land part)
21d Outer peripheral surface 21e Step part 21f Step part 21g End face 21h End face 21i Notch 21j Notch 80 Hydraulic control mechanism 86 Control valve (hydraulic control valve)
d gap w width

Claims (2)

A tubular valve body having a plurality of ports formed on the peripheral wall;
A spool valve provided in the valve body so as to be slidable and formed with a land portion having an outer peripheral surface slidably in contact with an inner peripheral surface of the valve body, the spool valve being in a sliding position with respect to the valve body. A hydraulic control valve that controls the hydraulic pressure supplied to the equipment by changing the opening area of the port on the outer peripheral surface accordingly,
A step portion formed on the outer peripheral surface, having a predetermined width in the sliding direction of the spool valve from an end surface of the land portion, and forming a predetermined gap with the inner peripheral surface ;
A notch formed in the stepped portion and notched in the moving direction of the spool valve from the end surface;
With
Hydraulic fluid flows into the valve body through the predetermined gap from the port ;
The hydraulic control valve according to claim 1 , wherein the notch is shorter than the predetermined width in the moving direction of the spool valve. A tubular valve body having a plurality of ports formed on the peripheral wall;
A spool valve provided in the valve body so as to be slidable and having a land portion having an outer peripheral surface in sliding contact with an inner peripheral surface of the valve body;
A hydraulic control valve for controlling the hydraulic pressure supplied to the equipment by changing the opening area of the port on the outer peripheral surface according to the sliding position of the spool valve with respect to the valve body,
A step portion formed on the outer peripheral surface, having a predetermined width in the sliding direction of the spool valve from an end surface of the land portion, and forming a predetermined gap with the inner peripheral surface;
A notch formed in the stepped portion and notched in the moving direction of the spool valve from the end surface;
In the moving direction of the spool valve, the notch is shorter than the predetermined width.
A hydraulic control valve characterized by that.

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