JP3474902B2 - Hydraulic valve - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic valve used in a hydraulic control device for an automatic transmission.

[0002]

2. Description of the Related Art As a conventional hydraulic valve, Japanese Patent Application Laid-Open No. 1-1
There is a shift valve disclosed in Japanese Patent No. 16347. When a part of this is taken out and shown in principle, it becomes as shown in FIG. That is, the spool 1 has the first land 2 and the second land 3 having a diameter smaller than that of the first land 2. The valve body has three ports 4, 5 and 6
Governor pressure corresponding to the vehicle speed acts on ports 4 and 5,
On the other hand, port 6 is always drained. Spool 1
Is always subjected to a force in the right direction in the figure by, for example, a spring. In the state of FIG. 4A (downshift state), the force pushing the spool 1 to the left is from the port 4 to the first position.
From the force due to the governor pressure acting on the entire right end of the land 2,
The force due to the governor pressure acting on the area difference between the first land 2 and the second land 3 is subtracted from the port 5. That is, it is a force corresponding to the governor pressure acting on the entire diameter of the second land 3. When the governor pressure rises, the force causes the spool 1 to move leftward. When moved to the state of FIG. 4B, the space between the first land 2 and the second land 3 communicates with the port 6 and is drained. Therefore, the force due to the governor pressure acting between the first land 2 and the second land 3 disappears, and only the governor pressure force acting on the right end surface of the first land 2 acts on the spool 1. That is, the force acting to the left sharply increases at the time of FIG. 4 (b). Therefore, as shown in FIG. 4C, the spool 1 rapidly moves to the left (switches from the downshift state to the upshift state). On the other hand, when the governor pressure decreases from the state of FIG. 4C (when switching from the upshift state to the downshift state), the force due to the governor pressure that acts on the entire right end surface of the first land 2 The switching point is determined by the force of the spring. Therefore, the hydraulic pressure of the governor pressure is different when the spool moves to the left (upshift) and to the right (downshift) (that is, upshift and downshift). Hysteresis is provided between).

[0003]

However, the conventional hydraulic valve as described above has a problem that the spool easily sticks and a problem that the spool is large in the axial direction. That is, the spool is (c) in FIG.
If the spool tilts while moving from (b) to (a),
As shown in (d), the edge 7 of the spool may hit the corner of the groove of the valve body and stop. Further, since there are two ports on which the governor pressure acts, the spool becomes long and the space required for disposing the hydraulic valve increases. The present invention aims to solve such problems.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above problems by communicating hydraulic pressure by a notch provided in a land of a spool. That is, the hydraulic valve according to the present invention is a hydraulic valve in which the spool (10) switches between two positions according to the magnitude of the acting signal pressure, and is a signal when switching from the first position to the second position. Pressure and second
Assuming that the signal pressure at the time of switching from the position to the first position is different, the spool (10) is
It has the 1st land (12) and the 2nd land (14) whose diameter is larger than this, and the 1st land (12) has an end part on the opposite side to the 2nd land (14) facing side. To the middle of the first land (12) in the axial direction, the first cutout portion (16) is provided, and the second land (14) is provided with the first land (1).
2) A second notch (18) is provided from the end opposite to the facing side to the axial middle of the second land (14), and the valve body is fitted with the first land (12). A first hole (20) and a second land (14) that can be fitted are provided with a second hole (22) that can be fitted, and between the first hole (20) and the second hole (22). An intermediate chamber (24) having a diameter larger than that of the second hole (22) is formed, and a signal pressure is supplied to the opposite side of the first hole (20) facing the intermediate chamber (24). A first oil chamber (26) is formed, and a drained second oil chamber (30) is always formed on the opposite side of the second hole (22) facing the intermediate chamber (24). When the spool (10) is in the first position, the first oil chamber (26) and the intermediate chamber (24) are shut off by the first land (12). Is, the second oil chamber (30) intermediate chamber (24) a second notch of the second land (14) (1
8), and when the spool (10) is in the second position, the first oil chamber (26) and the intermediate chamber (24) communicate with each other through the first cutout portion (16) of the first land (12). Then, the second oil chamber (30) and the intermediate chamber (24) are shut off by the second land (14), and the spool (10) is at an intermediate position between the first position and the second position, and the first land. (1
The second oil chamber (26) is formed by the first notch (16) of (2).
And the intermediate chamber (24) start to communicate with each other, the communication between the second oil chamber (30) and the intermediate chamber (24) by the second cutout portion (18) of the second land (14) is blocked. To begin, the spool (10) and valve body dimensions are set.

[0005]

When the signal pressure acting on the first oil chamber gradually increases from the state where the spool is at the first position, the spool starts moving toward the second position. At the same time as the first oil chamber and the intermediate chamber start communicating with each other due to the notch portion of the first land,
The communication between the second oil chamber and the intermediate chamber by the second cutout portion of the second land begins to be blocked. As a result, the spool has a second
Due to the hydraulic pressure acting on the oil chamber, the force toward the first position is also received, and the force rapidly moves to the second position. That is,
When moving from the first position to the second position, the switching is determined by the signal pressure acting on the end surface of the first land. On the other hand, when moving from the second position to the first position,
The switching is determined by the signal pressure acting on the first oil chamber and the intermediate chamber. That is, the switching condition is determined by the signal pressure acting on the entire second land. As a result, the magnitude of the signal pressure is different between when the first position is switched to the second position and when the second position is switched to the first position. The first land and the second land of the spool have an arcuate shape that fits into the first hole and the second hole, except for the portion where the first cutout portion and the second cutout portion are provided, respectively. Therefore, the first land and the second land always move while being guided by the first hole and the second hole, and the spool does not tilt. Therefore, no stick occurs.

[0006]

EXAMPLE FIG. 1 shows an example. The spool 10 is the first
The land 12 and the second land 14 having a diameter larger than that of the land 12 are provided. The first land 12 is provided with a first cutout portion 16 from an end portion on the opposite side of the second land 14 to the opposite side to an intermediate position in the axial direction of the first land 12. The second land 14 is also provided with a second cutout portion 18 from an end portion on the opposite side of the first land 12 facing the first land 12 to an axial midpoint of the second land 14. FIG. 2 is a perspective view of the spool 10. The valve body to which the spool 10 is fitted has a first hole 20 into which a first land 12 can be fitted.
And a second hole 22 into which the second land can fit. An intermediate chamber 24 having a diameter larger than that of the second hole 22 is formed between the first hole 20 and the second hole 22. A first oil chamber 26 is formed on the side of the first hole 20 opposite to the side facing the intermediate chamber 24, and this is connected to the first port 28. A second oil chamber 30 is formed on the side of the second hole 22 opposite to the side facing the intermediate chamber 24. Second
The oil chamber 30 is always drained via the second port 32. In the first position of FIG. 1A, the first oil chamber 2
6 and the intermediate chamber 24 are isolated from each other by the first land 12. On the other hand, the second oil chamber 30 and the intermediate chamber 24 are communicated with each other by the second cutout portion 18 of the second land 14. Figure 1
In the second position shown in (c), the first oil chamber 26 and the intermediate chamber 24 communicate with each other through the first cutout portion 16 of the first land 12, and the second oil chamber 30 and the intermediate chamber 24 are in the second position. Land 14
Blocked by. As shown in FIG. 1B, when the spool 10 is at the intermediate position, at the position where the first oil chamber 26 and the intermediate chamber 24 start to communicate with each other by the first cutout portion 16 of the first land 12, The axial dimensions of the first notch portion 16 and the second notch portion 18 are set so that the communication state between the second oil chamber 30 and the intermediate chamber 24 by the second notch portion 18 of the second land 14 begins to be blocked. It is set.

Next, the operation of this embodiment will be described. When the spool 10 shown in FIG. 1A is in the first position, the throttle pressure (signal pressure) acts from the first port 28, and when the throttle pressure gradually rises, the spool 10 acts leftward in the figure. The power to do will increase. It is assumed that a constant force in the right direction in FIG. 1 acts on the spool 10 by a spring (not shown).
At this time, the force acting on the spool 10 is the first land 12
The total area of is multiplied by the throttle pressure. When the spool 10 is moved to the position shown in FIG. 1B, the first oil chamber 26 and the intermediate chamber 24 communicate with each other by the first cutout portion 16 of the first land 12. At the same time, the intermediate chamber 24 and the second oil chamber 30 are shut off. Therefore, the throttle pressure acts on the intermediate chamber 24. Therefore, the throttle pressure acts on the entire area of the second land 14.
As a result, the force acting to the left on the spool 10 increases discontinuously at the time of FIG. 1 (b), and the spools are rapidly switched to the state of FIG. 1 (c). As described above, when the spool 10 moves to the left in FIG. 1, the switching point is determined by the force of the throttle pressure acting on the entire area of the first land 12.

Next, when the spool 10 moves to the right from the state shown in FIG. 1C, the throttle pressure acting on the first oil chamber 26 and the intermediate chamber 24 gradually decreases. become. Spool 10 due to reduced throttle pressure
1 moves to the state of FIG. 1B, the first oil chamber 26 and the intermediate chamber 24 are shut off and the intermediate chamber 24 and the second oil chamber 30 communicate with each other. Therefore, the hydraulic pressure in the intermediate chamber 24 is drained. At this point, the throttle pressure, which has been acting on the entire second land 14 until then, only acts on the area of the first land 12, and the force acting on the spool 10 is rapidly reduced, so that the spool 10 rapidly moves. Figure 1 (a)
Switch to the state of. As described above, when the spool 10 moves to the right, the switching point is determined by the magnitude of the throttle pressure that acts on the entire area of the second land 14. Therefore, the throttle pressure when the spool 10 moves leftward is larger than the throttle pressure when the spool 10 moves rightward. That is, a hysteresis is provided for switching the valve. The first land 12 of the spool 10 is moved during the movement of FIGS. 1 (a), 1 (b) and 1 (c).
And the second land 14 are the first hole 20 and the second hole 2, respectively.
Always supported by 2. Explaining the first land 12, the first cutout portion 16 is provided, but other portions in the circumferential direction where the first cutout portion 16 is not provided are the first land 1.
It has an arc-shaped outer diameter having the same diameter as the other portions of No. 2, and since it fits in the first hole 20, the spool 10 does not tilt. The same applies to the second land 14. Therefore, the edge of the spool 10 does not catch on the corner of the hole and generate a stick.

In the above embodiment, the first valve of the valve 10 is
Although the first notch portion 16 and the second notch portion 18 are provided on the land 12 and the second land 14, respectively, as shown in FIG. 3, instead of the first notch portion 16 and the second notch portion 18, ,
The communication holes 40 and 42 are formed in the first land 12 and the second land, respectively.
Even if it is provided so as to communicate from the end surface of the land 14 to the outer diameter portion, it is possible to obtain the same operation as that of the above embodiment.

[0010]

As described above, according to the present invention, the stick of the spool does not occur because the land is always supported by the hole of the valve body during the movement of the spool. Moreover, since the number of ports on which the signal pressure acts is sufficient, the total length of the hydraulic valve can be shortened.

[Brief description of drawings]

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

FIG. 2 is a perspective view of a spool.

FIG. 3 is a diagram showing a second embodiment.

FIG. 4 is a diagram showing a conventional hydraulic valve.

[Explanation of symbols]

10 spools 12 1st land 14 Second Land 16 First notch 18 Second notch 20 first hole 22 second hole 24 Intermediate room 26 First Oil Chamber 30 Second oil chamber

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) F16K 31/12 F16H 61/06 F16K 3/24

Claims (2)

(57) [Claims] 1. A hydraulic valve in which a spool (10) switches between two positions in accordance with the magnitude of an acting signal pressure, the signal pressure when switching from a first position to a second position, and Two
In the structure in which the signal pressure when switching from the position to the first position is different, the spool (10) includes a first land (12) and a second land (14) having a larger diameter than this. Has and first
The land (12) has a first end extending from the end opposite to the second land (14) facing side to an axial midpoint of the first land (12).
A notch (16) is provided, and the second land (1
4) is provided with a second notch portion (18) from the end opposite to the first land (12) facing side to the middle of the second land (14) in the axial direction. A first hole (20) capable of fitting the first land (12) and a second hole (22) capable of fitting the second land (14) are provided.
0) and the second hole (22), an intermediate chamber (24) having a diameter larger than that of the second hole (22) is formed.
The first oil chamber (26) to which the signal pressure is supplied is formed on the side opposite to the side facing the intermediate chamber (24) of (0) and the intermediate chamber (24) of the second hole (22). A drained second oil chamber (30) is always formed on the opposite side to the facing side, and when the spool (10) is at the first position, the first oil chamber (26) and the intermediate chamber (24) are formed. ) Is blocked by the first land (12), the second oil chamber (30) and the intermediate chamber (24) are communicated with each other by the second cutout portion (18) of the second land (14), and the spool (10 ) Is in the second position, the first oil chamber (26) and the intermediate chamber (24) communicate with each other through the first cutout portion (16) of the first land (12), and the second oil chamber (30).
And the intermediate chamber (24) are shut off by the second land (14), the spool (10) is at an intermediate position between the first position and the second position, and the first cutout portion of the first land (12). At a position where the first oil chamber (26) and the intermediate chamber (24) start to communicate with each other by the (16), the second oil chamber (30) and the second oil chamber (30) formed by the second cutout portion (18) of the second land (14) are intermediate. The spool (10) is started so that the communication with the chamber (24) begins to be cut off.
And the dimensions of the valve body are set. 2. Communication holes (40, 42) are provided in place of the first cutout portion and the second cutout portion, respectively, for communicating between the outer diameter portion and the end portions of the first land and the second land, respectively. The hydraulic valve according to claim 1, which is provided.