JPH0536120Y2 - - Google Patents

Description

[Detailed explanation of the idea]

INDUSTRIAL APPLICATION FIELD The present invention relates to a mechanism for removing dust from hydraulic fluid in a hydraulic control device used in an automatic transmission. Prior Art This type of dust removal mechanism includes, for example, the one shown in Hydraulic Technology Handbook (published by Nikkan Kogyo Shimbun, September 1962). That is, this automatic transmission to which this is applied has a plurality of orifice circuits c and d in which orifices a and b are formed, as shown in FIG.
The orifice circuits c and d have solenoid valves e and f on the downstream side of the orifices a and b, respectively.
The solenoid valves e and f are electromagnetically driven according to the vehicle operating condition to control driving fluid pressure such as line pressure introduced into the orifice circuits c and d. A signal pressure is generated on the downstream side of the orifices a and b, and a control valve (not shown) is actuated or controlled by this signal pressure. By the way, if dust containing iron powder or the like is mixed in the driving fluid pressure, the dust may adhere to the vicinity of the solenoid valve due to solenoid magnetization, causing malfunction, or the orifices a and b may be blocked by the dust. Otherwise, it becomes impossible to obtain accurate signal pressure. Therefore, conventionally, strainers g and h are provided on the upstream side of the orifices a and b, respectively, to prevent the dust from passing toward the orifices a and b due to overfunction of the strainers g and h. , such strainers g and h constitute a dust removal mechanism. Problems to be Solved by the Invention However, in such a conventional dust removal mechanism, strainers g and h are provided on the upstream side of each orifice a and b, respectively. Strainers g and h are provided in a number corresponding to the number b, which greatly increases the number of parts. In addition, providing such a large number of strainers g, h requires the individual strainers g, h to be downsized due to the mounting space of the valve body, which inevitably results in a narrow working fluid passage area of the strainers g, h. This resulted in problems such as worsening of overfunction and increased hydraulic fluid passage resistance. In addition, a single strainer is installed on the upstream side (frontstream side) of the oil pump to obtain the line pressure shown in Figure 3, so that when the oil pump sucks oil from the oil pan, iron powder contained in the oil It is also possible to remove dust. However, in this case, if the filtration performance of the strainer is increased to the level required for the solenoid valve and orifice, the suction resistance of the oil pump will increase, which is undesirable. Therefore, the present invention aims to reduce the number of parts and increase the passage area of the strainer by sharing the strainer for each orifice circuit without causing an increase in suction resistance of the oil pump. An object of the present invention is to provide a dust removal mechanism for a hydraulic pressure control device for a transmission. Means for Solving the Problems In order to achieve the above object, the dust removal mechanism of the automatic transmission hydraulic pressure control device of the present invention uses a common driving hydraulic pressure regulated to a constant pressure by a pilot valve. A plurality of orifice circuits are introduced through each orifice, and each orifice circuit has a solenoid valve provided on the downstream side of the orifice which is electromagnetically driven according to the vehicle driving condition. In a hydraulic pressure control device for an automatic transmission that generates a signal pressure on the flow side, the upstream sides of the plurality of orifice circuits are combined into one collective circuit, and of this collective circuit, the upstream side of the plurality of orifice circuits is A strainer common to each of the orifice circuits is provided on the flow side. In the dust removal mechanism of the present invention with the above configuration, the driving fluid pressure introduced into each orifice circuit is as follows:
After passing through a pilot valve, it passes through a common strainer provided in the collective circuit to be supplied with dust removed. Therefore, by providing a common strainer on the downstream side of the pilot valve, only one strainer is required for each orifice circuit, and the space that can be occupied by the strainer is limited to the space occupied by the strainer provided in each of the orifice circuits. Therefore, the strainer space that is no longer provided can be expanded by integrating it, and it also avoids increasing the suction resistance of the oil pump, as would be the case if a strainer was installed on the upstream side (suction side) of the oil pump. Nor. Therefore, it is possible to increase the size of the common strainer, increase the working fluid passage area through the strainer, reduce the working fluid passage resistance, and increase the dust removal function. Embodiments Hereinafter, embodiments of the present invention will be described in detail based on the drawings. That is, FIG. 1 is an overall circuit showing an embodiment of a hydraulic pressure control device for an automatic transmission using the dust removal mechanism of the present invention, and a power transmission train of an automatic transmission controlled by this hydraulic pressure control device. For example, there is one shown in the schematic diagram of FIG. That is, this power transmission train transfers the rotation from the engine output shaft 1 to the input shaft 2.
It consists of a torque converter 3, a first planetary gear set 4, a second planetary gear set 5, an output shaft 6, and various friction elements described below. The torque converter 3 is driven by the engine output shaft 1 and includes a pump impeller 3P that is also used to drive the oil pump O/P, and a turbine that is fluidly driven by the pump impeller via internal working fluid and transmits power to the input shaft 2. placed on a fixed shaft via a runner 3T and a one-way clutch 7,
It consists of a stator 3S that increases the torque to the turbine runner 3T, and a lock-up clutch 3 is attached to this stator 3S.
This is a normal lock-up torque converter with L added. The torque converter 3 is supplied with working fluid from the release chamber 3R, and while the working fluid is removed from the apply chamber 3A, the lock-up clutch 3L is released and the engine power is pumped through the impeller 3P and the turbine runner 3T ( (in the converter state) torque is transmitted to the input shaft 2 while increasing, and while the working fluid is being supplied from the abrasion chamber 3A and being removed from the release chamber 3R, the lock-up clutch 3L is engaged and the engine power is increased. is transmitted as is to the input shaft 2 via this lock-up clutch (in the lock-up state). In the latter lock-up state, the slip of the lock-up torque converter 3 (relative rotation of the pump impeller 3P and the turbine runner 3T) is arbitrarily controlled (slip control) by reducing the working fluid displacement pressure from the release chamber 3R. be able to. The first planetary gear set 4 is a normal simple planetary gear set consisting of a sun gear 4S, a link gear 4R, a pinion 4P that meshes with these gears, and a carrier 4C that rotatably supports the pinion 4P.
Sun gear 5S, link gear 5R, pinion 5P
and carrier 5C. Next, the various friction elements mentioned above will be explained. The carrier 4C can be appropriately connected to the input shaft 2 via a high clutch H/C, and the sun gear 4S can be appropriately fixed by a band brake B/B, and can also be appropriately connected to the input shaft 2 by a reverse clutch R/C. . The Carrier 4C can be fixed appropriately with a multi-plate low reverse brake LR/B, and
Reverse rotation (rotation in the opposite direction to the engine) is prevented via the row one-way clutch LO/C. Link gear 4R is integrally connected to carrier 5C and output shaft 6
The sun gear 5S is coupled to the input shaft 2. Link gear 5R is an overrun clutch
In addition to being able to connect to carrier 4C as appropriate via OR/C, forward one-way clutch FO/C
and is correlated to the carrier 4C via the forward clutch F/C. The forward one-way clutch FO/C connects the link gear 5R to the carrier 4C in the reverse direction (the direction opposite to the engine rotation) when the forward clutch F/C is engaged. High clutch H/C, reverse clutch R/
C, low reverse brake LR/B, overrun clutch OR/C and forward clutch F/
C is operated by hydraulic pressure supply to perform the above-mentioned appropriate coupling and fixing, but band brake B/B is connected to 2-speed servo apply chamber 2S/A,
When the 3rd speed servo release chamber 3S/R and the 4th speed servo apply chamber 4S/A are set and the 2nd speed selection pressure P ₂ is supplied to the 2nd speed servo apply chamber 2S/A, the band brake B/B is activated. In this state, when the 3rd speed selection pressure _P3 is also supplied to the 3rd speed servo release chamber 3S/R, the band brakes B/B are deactivated.
After that, when 4th gear selection pressure P ₄ is also supplied to 4th gear servo apply chamber 4S/A, band brake B/B
is starting to work. Such a power transmission train includes friction elements B/B, H/
By operating C, F/C, OR/C, LR/B, and R/C in various combinations as shown in the table below,
Together with the appropriate operation of the friction elements FO/C and LO/C, the rotational state of the elements constituting the planetary gear sets 4 and 5 is changed, thereby changing the rotational speed of the output shaft 6 side relative to the rotational speed of the input shaft 2. As shown in the table below, it is possible to obtain four forward speeds and one reverse speed. Note that in the table below, the ○ mark indicates operation (hydraulic inflow), while the 〓 mark indicates a friction element that should be activated when engine braking is required. And, 〓
As shown in the figure, while the overrun clutch OR/C is activated, the forward one-way clutch FO/C placed parallel to it is inactive, and while the low reverse brake LR/B is activated, the row one-way clutch placed parallel to it is inactivated. Of course, the clutch LO/C becomes inoperative.

[Table] By the way, the hydraulic pressure control device shown in FIG. 1 includes a pressure regulator valve 20, a pressure modifier valve 22, and a duty solenoid 2.
4, pilot valve 26, torque converter regulator valve 28, lockup control valve 3
0, shuttle valve 32, duty solenoid 3
4, manual valve 36, first shift valve 38, second
Shift valve 40, first shift solenoid 42, second
Shift solenoid 44, forward clutch control valve 46, 3-2 timing valve 48, 4-
2 relay valve 50, 4-2 sequence valve 52,
Range pressure reducing valve 54, shuttle valve 56, overrun clutch control valve 58, third shift solenoid 60, overrun clutch pressure reducing valve 62,
The main components are a 2nd speed servo apply pressure accumulator 64, a 3rd speed servo release pressure accumulator 66, a 4th speed servo apply pressure accumulator 68, and an accumulator control valve 70, which are connected to the torque converter 3, forward clutch F/ C. Configure and connect to high clutch H/C, band brake B/B, reverse clutch R/C, low reverse brake LR/B, overrun clutch OR/C, and oil pump O/P as shown. . The pressure regulator valve 20 has a spool 20b elastically supported at the left half position in the figure by a spring 20a.
and the plug 2 that abuts against the lower end surface of the spool in the figure.
Basically, the oil pump O/P regulates the oil discharged to the circuit 71 to a certain pressure determined by the spring force of the spring 20a, but the plug 20c applies an upward force to the spool 20b in the figure. When the line pressure is increased, the above pressure is increased accordingly to reach a predetermined line pressure. For this purpose, the pressure regulator valve 20 is configured to receive the pressure in the circuit 71 via the damping orifice 72 to the pressure receiving surface 20d of the spool 20b, thereby biasing the spool 20b downward. Ports 20e to 20h open and close depending on the stroke position of 20b
will be established. Port 20e is connected to circuit 71, and is arranged so that as spool 20b descends from the left half position in the figure, it communicates with ports 20h and 20f.
The port 20f is arranged so that as the spool 20b descends from the left half position in the figure, communication with the port 20g serving as a drain port is reduced, and at the point when communication with this port is cut off, communication with the port 20e begins. And Plead 7 on the way to port 20f
Oil pump O/P via circuit 74 where 3 exists.
is connected to the capacity control actuator 75 of. The oil pump O/P is a variable capacity vane pump driven by the engine as described above, and the eccentricity is reduced when the pressure toward the actuator 75 exceeds a certain value, so that the capacity becomes smaller. The plug 20c of the pressure regulator valve 20 receives the modifier pressure from the circuit 76 on its lower end face in the figure, and receives the backward selection pressure from the circuit 77 on the pressure receiving surface 20i, and the plug 20c receives the modifier pressure from the circuit 77 on its lower end face in the figure, and receives the backward selection pressure from the circuit 77 on the pressure receiving surface 20i, and the plug 20c receives the modifier pressure from the circuit 77 on its lower end face in the figure, and receives the backward selection pressure from the circuit 77 on the pressure receiving surface 20i. Assume that a force of is applied to the spool 20b. The pressure regulator valve 20 is normally in the left half state in the figure, and when oil is discharged from the oil pump O/P, this oil flows into the circuit 71. Circuit 7 at the left half position of spool 20b
The oil in No. 1 is not drained at all, and the pressure increases.
This pressure acts on the pressure receiving surface 20d through the orifice 72, pushes down the spool 20b against the spring 20a, and connects the port 20e to the port 20h. As a result, the above pressure is partially drained from the port 20h and lowered, and the spool 20b is pushed back by the spring 20a. By repeating this action, the pressure regulator valve 20 basically operates in the circuit 71.
The pressure inside (hereinafter referred to as line pressure) is set to a value corresponding to the spring force of the spring 20a. By the way, plug 2
An upward force from the modifier pressure from the circuit 76 acts on 0c, causing the plug 20c to come into contact with the spool 20b as shown in the right half of the figure, and this upward force is applied to the spool 20b to assist the spring 20a, and As will be described later, the modifier pressure is generated when the vehicle is not in reverse mode and increases in proportion to the engine load (engine output torque), so the above-mentioned line pressure increases as the engine load increases other than when the reverse mode is selected. When reversing is selected, an upward force is applied to the plug 20c by the retracting selection pressure (same value as the line pressure) from the circuit 77 instead of the modifier pressure described above, and this is applied to the spool 20b, so that the line pressure is kept at a desired constant value when reversing is selected. becomes. When the oil pump O/P reaches a certain rotational speed or higher (the engine rotates at a certain rotational speed or higher), the oil discharge amount that increases accordingly becomes excessive, and the pressure within the circuit 71 exceeds the pressure regulation value. This pressure lowers the spool 20b further from the pressure regulating position in the right half of the figure, communicates the port 20f with the port 20e, and blocks it from the drain port 20g. As a result, some of the oil in the port 20e is removed from the port 20f and the lead 73, but feedback pressure is generated in the circuit 74. This feedback pressure increases as the rotational speed of the oil pump O/P increases, and reduces the eccentricity (capacity) of the oil pump O/P via the actuator 75. In this way, the capacity of the oil pump O/P is controlled so that the discharge amount remains constant while the rotational speed exceeds a certain value, and the power loss of the engine is prevented from increasing due to discharging more oil than necessary. . As mentioned above, the line pressure generated in the circuit 71 is transferred to the pilot valve 26, the manual valve 36, and the accumulator control valve 70 by the line pressure circuit 78.
and a third-speed servo release pressure accumulator 66. The pilot valve 26 includes a spool 26b elastically supported in the upper half position in the figure by a spring 26a, and the end face of the spool 26b far from the spring 26a is connected to a chamber 26c.
The pilot valve 26 is further provided with a drain port 26d and is connected to a pilot pressure circuit 79a via a collective circuit 79. A communication hole 26e is provided in the spool 26b to guide the pressure of the pilot pressure collection circuit 79 to the chamber 26c, and the circuit 79 is switched and connected from the circuit 78 to the drain port 26d as it goes to the right in the figure. The pilot valve 26 is normally in the upper half state in the figure, and when it is supplied with line pressure from the circuit 78, it increases the pressure in the circuit 79. The pressure in the circuit 79 reaches the chamber 26c through the communication hole 26e, causing the spool 26b to move to the right in the figure, and when the spool 26b exceeds the pressure regulating position shown in the lower half, the circuit 79 is cut off from the circuit 78, and at the same time, the drain port 26
Leads to d. At this time, the pressure in circuit 79 is reduced,
This pressure drop causes the spool 26b to spring 26a.
When pushed back, the pressure in the circuit 79 rises again. In this way, the pilot valve 26 can reduce the line pressure from the circuit 78 to a constant value determined by the spring force of the spring 26a, and output it as pilot pressure to the collective circuit 79 and the pilot pressure circuit 79a. This pilot pressure is supplied to the pressure modifier valve 22, duty solenoids 24, 34, lock-up control valve 30,
Forward clutch control valve 46, shuttle valve 32, first, second, and third shift solenoids 4
2, 44, 60, and the shuttle valve 56. The duty solenoid 24 consists of a coil 24a, a spring 24d, and a plunger 24b.
Pilot pressure circuit 79a via orifice 80
The orifice circuit 81 connected to the coil 24a
When ON (energized), it communicates from the drain port 24c. This duty solenoid 24 has a coil 24a turned on and off at a constant cycle by a computer (not shown), and the ratio of ON time to the constant cycle (duty ratio) is controlled, and a circuit 81 is connected to the coil 24a according to the duty ratio. generates control pressure. The duty ratio is the engine load (e.g. engine throttle opening) except when reverse is selected.
As the engine load increases, the control pressure increases as the engine load increases. Further, when selecting reverse, the duty ratio is set to 100%, and the above control pressure is set to 0. The pressure modifier valve 22 has a spring 22a.
The pressure modifier valve 22 further includes an output port 22c to which the circuit 76 is connected, and a pilot pressure circuit 79a.
An input port 22d and a drain port 22e are provided to connect the spool 22 far from the spring 22a.
A circuit 76 is connected to the chamber 22f facing the end surface of b.
These ports are arranged so that the port 22c is exactly blocked from the ports 22d and 22e at the left half of the spool 22b in the figure. The pressure modifier valve 22 has a spring 22
The spool 22b receives the spring force from a and the force from the control pressure from the circuit 81 downward in the figure, and the spool 22b receives the force due to the output pressure from the port 22c that has reached the chamber 22f upward in the figure. The spool 22b is stroked to a balanced position. If the output pressure from the port 22c is insufficient to match the downward force, the spool 22b will descend beyond the pressure regulating position shown in the left half, and at this time the port 22c will communicate with the port 22d, and the circuit will be closed. The output pressure is increased in response to replenishment of pilot pressure from 79a. Conversely, if this output pressure is too high to match the downward force, the spool 22b will rise toward the right half position in the figure. At this time, the port 22c communicates with the drain port 22e, and the output pressure is reduced. By repeating this action, the pressure modifier valve 22 adjusts the output pressure from the port 22c to a value corresponding to the sum of the spring force of the spring 22a and the control pressure from the circuit 81, and adjusts this to the modifier pressure. This is supplied from the circuit 76 to the plug 20c of the pressure regulator valve 20. By the way, as mentioned above, the control pressure increases as the engine load increases except when reverse is selected, and is 0 when reverse is selected, so the modifier pressure is also a value obtained by amplifying this control pressure by the spring force of the spring 22a. It increases as the engine load increases except when the reverse is selected, and becomes 0 when the reverse is selected, allowing the pressure regulator valve 20 to control the line pressure described above. Torque converter regulator valve 28 has spring 2
8a, the spool 28b is elastically supported in the right half position in the figure, and the port 28
c to the port 28d, and as the spool 28b rises from the left half position in the figure, the port 28c
The degree of communication is decreased for port 28d, port 2
It is assumed that the degree of connectivity is increased relative to 8e. In order to control the stroke of the spool 28b, a chamber 28f facing the spool end face far from the spring 28a is communicated with the port 28c through a communication hole 28g provided in the spool 28b. The port 28c is connected to a predetermined lubricating part via a relief valve 82 and connected to the lockup control valve 30 via a circuit 83, and the port 28d is connected to the port 20 of the pressure regulator valve 20 via a circuit 84.
h, and port 28e is connected by circuit 85 to lockup control valve 30. circuit 8
5 has an orifice 86 in the middle, and the orifice and port 28c are connected to a circuit 83 via an orifice 87, and are communicated to an oil cooler 89 and a predetermined lubricating section 90 by a circuit 88. The torque converter regulator valve 28 is normally in the right half state in the figure, where oil flows from the port 20h of the pressure regulator valve 20 to the circuit 8.
4, this oil is directed from circuit 83 to torque converter 3 as described below. When supply pressure to the torque converter is generated, this torque converter supply pressure is applied to the communication hole 2.
8g, the chamber 28f is reached, and the spool 28b is raised against the spring 28a in the figure. When the spool 28b rises from the left half position in the figure due to an increase in the torque converter supply pressure, the port 28e opens and a portion of the torque converter supply pressure is removed through the port 28e and the circuit 88, thereby reducing the torque converter supply pressure. The pressure is adjusted to a value determined by the spring force of the spring 28a. The oil removed from the circuit 88 is cooled by an oil cooler 89 and then directed to a lubricating section 90. In addition, the torque converter regulator valve 28
If the torque converter supply pressure exceeds the above value even with the above-mentioned pressure regulating action, the relief valve 82 opens and the excess pressure is released to the corresponding lubricating section, thereby preventing deformation of the torque converter 3. The lock-up control valve 30 is connected to the spool 3
0a and the plug 30b coaxially butted,
When the spool 30a is at the limit position shown in the right half, the circuit 83 is connected to the circuit 91 from the torque converter release chamber 3R, and when the spool 30a is lowered to the left half position in the figure, the circuit 83 is connected to the circuit 85. When the spool 30a further descends, the circuit 91 is connected to the drain port 30c. In order to control the stroke of the spool 30a, the end face of the spool 30a far from the plug 30a faces the chamber 30d, and the orifice 9 is placed in the chamber 30e facing the end face of the plug 30b far from the spool 30a.
2 to lead the pressure of the circuit 91. Note that the circuit 93 from the torque converter apply chamber 3A is connected to the circuit 85 at a location closer to the lockup control valve 30 than the orifice 86. Further, the pilot pressure from the circuit 79 is applied to the plug 30b through the orifice 94 to continue applying a downward force in the figure, thereby preventing pulsation of the spool 30a. The lock-up control valve 30 controls the stroke of the spool 30a by the pressure supplied to the chamber 30d, and while this pressure is sufficiently high, the spool 30a
maintains the right half position in the figure. At this time, the oil from the circuit 83 flows through the circuit 91, the release chamber 3R, the apply chamber 3A, the circuit 93, and the circuit 85 under pressure regulation by the torque converter regulator valve 28.
Excluded from 8. Thus, the torque converter 3 transmits power in the converter state. As the pressure within chamber 30d decreases, spool 30a is forced to close plug 30 by pressure from orifices 92, 94.
b, and further descends from the left half position in the figure, the pressure regulating oil from circuit 83 flows to circuits 85, 93, apply chamber 3A, release chamber 3R, circuit 91, and drain port 30c. The torque converter 3 transmits power in a slip control state in which the slip decreases as the pressure in the chamber 30d decreases. When the pressure inside the chamber 30d is further reduced from this state, the spool 3
As 0a further falls, the circuit 91 is completely communicated with the drain port 30c, the pressure in the release chamber 3R is reduced to 0, and the torque converter 3 transmits power in a locked-up state. The shuttle valve 32 controls the stroke of the lockup control valve 30 together with a forward clutch control valve 46, which will be described later.
A spool 32b is elastically supported by 2a in the lower half position in the figure, and this spool is appropriately switched to the upper half position in the figure by the pressure inside the chamber 32c. The shuttle valve 32 connects the circuit 95 of the chamber 30d to the pilot pressure circuit 7 when the spool 32b is in the lower half position in the figure.
9a and extending from chamber 46a of forward clutch control valve 46.
6 is connected to the circuit 97 from the duty solenoid 34, and when the spool 32b is in the upper half position in the figure, the circuit 95 is connected to the circuit 97, and the circuit 96 is connected to the circuit 97.
is connected to the circuit 79a. The duty solenoid 34 is a plunger 34 elastically supported in a closed position by a coil 34a and a spring 34d.
b, and the orifice circuit 97 connected to the pilot pressure circuit 79a via the orifice 98,
Drain port 34 when coil 34a is ON (energized)
c. This duty solenoid 34 is controlled by a computer (not shown) to turn the coil 34a ON and OFF at a constant cycle, and also controls the ratio of the ON time to the constant cycle (duty ratio) to set the duty ratio in the orifice circuit 97. Generates appropriate control pressure. When the control pressure of the circuit 97 is used to control the stroke of the lock-up control valve 30 with the shuttle valve 32 in the upper half state in the figure, the duty ratio of the solenoid 34 is determined as follows. That is, under high load and low rotation speeds of the engine where the torque increasing function and torque fluctuation absorbing function of the torque converter 3 are absolutely necessary, the duty ratio is set to 0%, thereby keeping the control pressure of the circuit 97 at the original pressure. Make it the same as the pilot pressure of circuit 79a. At this time, the control pressure maintains the spool 30a in the right half position in the figure in the chamber 30d, and maintains the torque converter 3 in the converter state to meet the above requirements. As the demand for both of the above functions of the torque converter 3 becomes lower, the duty ratio is increased and the control pressure is lowered, thereby causing the torque converter 3 to function in a slip control state that matches the demand via the lock-up control valve 30. When the torque converter 3 is not required to perform both of the above functions at low engine load and high engine speed, the duty ratio is set to 100%, thereby setting the control pressure to 0 and requesting the torque converter 3 through the lock-up control valve 30. Keep the street locked up. Note that when the shuttle valve 32 is in the lower half state in the figure and the control pressure of the circuit 97 is used to control the stroke of the forward clutch control valve 46, the duty ratio of the solenoid 34 reduces the N→D selection shock as described later. determined to prevent creep. The manual valve 36 is operated by the driver to select parking (P) range, reverse (R) range, neutral (N) range, forward automatic shift (D) range, forward second gear engine brake () range, and first forward gear range.
A spool 36a is provided that is stroked to the high speed engine brake range, and a line circuit 78 is connected to ports 36D, 36, 36, and 36R according to the selected range of the spool as shown in the following table. In addition, the mark ○ in this table indicates line pressure circuit 7.
8, and unmarked ports indicate drained ports.

[Table] The first shift valve 38 includes a spool 38b elastically supported in the left half position in the figure by a spring 38a, and this spool is switched to the right half position in the figure when pressure is supplied to the chamber 38c. . When the spool 38b is in the left half position, the first shift valve 38 changes the port 38d to the drain port 38e and the port 38f to the drain port 38e.
to port 38g, port 38h to port 38i
When the spool 38b is in the right half position in the figure, the port 38d is connected to the port 38j, and the port 3 is connected to the port 38j.
8f to port 38k, port 38h to port 3
8l each. The second shift valve 40 includes a spool 40b elastically supported by a spring 40a in the left half position in the figure, and this spool assumes the right half position in the figure when pressure is supplied to the chamber 40c. and second shift valve 40
When the spool 40b is in the left half position in the figure, the port 40d is connected to the drain port 40e, the port 40f is connected to the port 40g, and the port 40h is connected to the drain port 40i with an orifice, and the spool 40
When b is in the right half position in the figure, port 40d is connected to port 4.
0j, port 40f to drain port 40e,
It is assumed that each port 40h is connected to a port 40k. The spool positions of the first and second shift valves 38 and 40 are controlled by a first shift solenoid 42 and a second shift solenoid 44, respectively, and these shift solenoids are connected to coils 42a and 44a, respectively.
and plungers 42b, 44b, spring 42
d, 44d. 1st shift solenoid 4
2 is connected to the pilot pressure circuit 79a via an orifice 99, and when the coil 42a is ON (energized), the orifice circuit 100 connected to the chamber 38c is shut off from the drain port 42c, and the orifice circuit 10 is connected to the pilot pressure circuit 79a.
The control pressure within 0 is set to the same value as the pilot pressure which is the source pressure, thereby switching the first shift valve 38 to the right half state in the figure. The second shift solenoid 44 is connected to the pilot pressure circuit 79a via the orifice 101, and turns the coil 44a ON (energized) through the orifice circuit 102 leading to the chamber 40c.
It is assumed that the control pressure in the circuit 102 is set to the same value as the original pilot pressure by shutting off the drain port 44c, thereby switching the second shift valve 40 to the right half state in the figure. Turn on these shift solenoids 42 and 44,
The first to fourth forward speeds can be obtained by combinations of the OFF states and, therefore, the states of the shift valves 38 and 40, which are summarized in the table below.

[Table] In this table, the ○ mark indicates the right half of the shift valve in the figure is in the raised state, and the × mark indicates the left half of the shift valve in the lower state.
ON and OFF are determined by a computer (not shown) that determines a suitable gear position from the vehicle speed and engine load based on a predetermined gear change pattern, and determines the suitable gear position to correspond to this gear position. The forward clutch control valve 46 includes a spool 46b on which the pilot pressure from the circuit 79a led through the orifice 103 is applied downward in the figure to prevent pulsation of the spool, and further on this spool. Orifice 1
04, the operating pressure of the forward clutch F/C in the circuit 105 is fed back and applied downward in the figure. The spool 46b is stroked to a position where the downward force in the figure due to these pressures and the force due to the pressure inside the chamber 46a are balanced. When the spool 46b is in the right half position in the figure, circuit 1
05 is connected to the drain port 46c, and when in the left half position in the figure, the circuit 105 is connected to the circuit 106, and the circuit 105 has a one-way orifice that exerts a throttling effect only on the hydraulic pressure directed to the forward clutch F/C. 107 is provided, and the circuit 106 is connected to the port 36D of the manual valve 36. 3-2 The timing valve 48 includes a spool 48b elastically supported at the left half position in the figure by a spring 48a. At this spool position, a port 48c and a port 48d with an orifice 48f communicate with each other, and the chamber 48
It is assumed that when the pressure in e is high and the spool 48b is at the right half position in the figure, the ports 48c and 48d are shut off. 4-2 The relay valve 50 includes a spool 50b elastically supported at the left half position in the figure by a spring 50a, and at this spool position, the port 50c is connected to the drain port 50d with an orifice, and pressure is supplied into the chamber 50e. It is assumed that when the spool 50b is at the right half position in the figure, the port 50c communicates with the port 50f. 4-2 The sequence valve 52 includes a spool 52b elastically supported in the right half position in the figure by a spring 52a, and in this spool position, the port 52c is connected to the drain port 52d with an orifice, and when the pressure in the chamber 52e is high, the spool 52b It is assumed that the port 52c is communicated with the port pressure 52f when it is at the left half position in the figure. The range pressure reducing valve 54 includes a spool 54b biased toward the right half position in the figure by a spring 54a, and a port 54c, which communicates with each other at this spool position.
54d, and a drain port 54e that begins to communicate with the port 54c when the spool 54b rises to the left half position in the figure and finishes closing the port 54d. A chamber 54f facing the end face of the spool 54b far from the spring 54a is connected to the port 54c via an orifice 108. Thus, the range pressure reducing valve 5
4 is in the normal state in the right half of the figure, and when pressure is supplied to the port 54d, pressure is output from the port 54c. This output pressure is the orifice 108
The pressure is applied to the lower end surface of the spool 54b in the figure, and as the output pressure increases, the spool 54b is raised in the figure. When the spool 54b rises above the left half position in the figure, the port 54c communicates with the drain port 54e and reduces the output pressure from the port 54c.
When the spool 54b is lowered by more than the left half position in the figure due to this output pressure drop, the port 54c is changed to the port 5.
4d and increases the output pressure from port 54c. By repeating this action, the output pressure from the port 54c is reduced to a constant value determined by the spring force of the spring 54a. The shuttle valve 56 includes a spool 56b elastically supported in the left half position in the figure by a spring 56a, and this spool is held in this position when there is a pressure supply to the chamber 56g; When the upward force in the figure due to the pressure from the port 56c exceeds a certain value, it is stroked to the right half position in the figure. At the left half position in the figure, the port 56d is connected to the circuit 109 from the third shift solenoid 60, and the port 56e is connected to the drain port 56f, and at the right half position in the figure, the port 56d is connected to the pilot pressure circuit 79a, and the port 56e is connected to the circuit 109. The third shift solenoid 60 includes a coil 60a, a plunger 60b, and a spring 60d.
Pilot pressure circuit 79 via orifice 110
The orifice circuit 109 connected to the coil 6
When 0a is ON (energized), the drain port 60c is shut off, and the control pressure in the circuit 109 is made to be the same value as the pilot pressure, which is the source pressure. In addition, the third
ON/OFF of the shift solenoid 60 is determined by a computer (not shown) as described below. It is assumed that the overrun clutch control valve 58 includes a spool 58b elastically supported in the left half position in the figure by a spring 58a, and this spool is switched to the right half position in the figure when pressure is supplied to the chamber 58c. In addition, the spool 58b is located at the left half position in the figure, and the port 58d is connected to the drain port 58e, and the port 58f is connected to the drain port 58e.
are connected to the port 58g, and at the right half position in the figure, the port 58d is connected to the port 58h, and the port 58f is connected to the drain port 58e. The overrun clutch pressure reducing valve 62 has a spring 62a.
The spool 62 is supported in the left half position in the figure by
b, and when there is pressure on this spool from port 62c, this applies a downward force in the figure to hold spool 62b in this position. While there is no pressure inflow from port 62c, port 62c
When pressure is supplied to port 62, this pressure
Increase the output pressure from e. This output pressure is in the chamber 62f
When the spool 62b is fed back to a value corresponding to the spring force of the spring 62a, the spool 62b is moved to the right half position in the figure, and the ports 62d and 62e are cut off.
The overrun clutch pressure reducing valve 62 is connected to the port 62e.
It is assumed that the output pressure from the spring 62a is reduced to a constant value determined by the spring force of the spring 62a. The 2-speed servo apply pressure accumulator 64 is constructed by elastically supporting a stepped piston 64a at the left half position in the figure by a spring 64b, and a chamber 64c defined between both ends of the stepped piston 64a is opened to the atmosphere. The small-diameter end face and large-diameter end face of the piston with
4d and 64e. The 3-speed servo release pressure accumulator 66 includes a stepped piston 66a elastically supported in the left half position in the figure by a spring 66b, and a chamber 66c defined between both ends of the stepped piston is connected to the line pressure circuit 78. The small-diameter end face and large-diameter end face of the stepped piston face the closed chambers 66d and 66e, respectively. The 4-speed servo apply pressure accumulator 68 is constructed by elastically supporting a stepped piston 68a at the left half position in the figure by a spring 68b, and defines a sealed chamber 68c between both ends of the stepped piston. The small diameter end face and the large diameter end face are sealed in sealed chambers 68d and 68, respectively.
Let's face e. Accumulator control valve 70 has spring 70
The spool 7 is supported in the left half position in the figure by a.
0b, and the spool 70b is remote from the spring 70a.
The control pressure of the circuit 81 is guided to the chamber 70c facing the end face of the circuit 81. The spool 70b connects the output port 70d to the drain port 70e at the left half position in the figure, and the spool 70b connects the output port 70d to the drain port 70e, and
When the control pressure increases and the spool 70b rises above the right half position in the figure, the port 70d is switched and connected to the line pressure circuit 78. and,
The output port 70d is connected to the accumulator chambers 64d and 68c by the circuit 111, and the spring 70
It is also connected to the chamber 70f that accommodates a. Thus, the accumulator control valve 70 raises the spool 70b above the right half position in the drawing by the control pressure applied to the chamber 70c except when the reverse movement is selected. As a result, the line pressure from the circuit 78 is output to the circuit 111, and when the pressure in the circuit 111 reaches a value corresponding to the control pressure, the spool 70b is elastically supported at the right half position in the figure. This is why circuit 11
The pressure of 1 is regulated to a value corresponding to the control pressure, but
Since the control pressure increases as the engine load (engine output torque) increases except when reverse is selected as described above, the accumulators 64 and 68 are removed from the circuit 111.
The pressure supplied to the chambers 64d and 68c as accumulator back pressure also increases as the engine output torque increases. In addition, since the control pressure is 0 when the reverse movement is selected, no pressure is output to the circuit 111. Next, to provide a supplementary explanation of the hydraulic circuit network, the circuit 106 extending from the port 36D of the manual valve 36 connects the port 38g of the first shift valve 38 and the second port 38g of the first shift valve 38.
While connecting to port 40g of shift valve 40,
It is also connected to port 56c of shuttle valve 56 and port 58g of overrun clutch control valve 58 via circuit 112 branched from circuit 106. The port 38f of the first shift valve 38 is connected to the circuit 11
3 is connected to the port 50f of the 4-2 relay valve 50, and is also connected to the accumulator chamber 64e and the 2-speed servo apply chamber 2S/A via the one-way orifice 114, and the port 50f is connected to the circuit 1
15, it is also connected to the chamber 32c of the shuttle valve 32. Furthermore, the port 38h of the first shift valve 38 is connected to the chamber 50e of the 4-2 relay valve 50 and the port 58h of the overrun clutch control valve 58 by a circuit 116, and the port 50c of the 4-2 relay valve 50 is connected to the chamber 50e of the 4-2 relay valve 50 by a circuit 117. Connected to port 40k of 2-shift valve 40. The ports 38k and 38l of the first shift valve 38 are connected to the port 4 of the second shift valve 40.
High clutch H/C by circuit 118 along with 0f
A pair of one-way orifices 119 and 120 arranged in opposite directions are inserted in the middle. A circuit 121 branched from the circuit 118 between these orifices and the high clutch H/C
is connected to the 3-speed servo release chamber 3S/R and the accumulator chamber 66 via the one-way orifice 122.
ports 48c and 48d are connected to the circuit 123 that bypasses the one-way orifice 122, and the 3-2 timing valve 48 is connected to the circuit 123 that bypasses the one-way orifice 122.
Insert into 3. A circuit 124 branched from the circuit 121 between the one-way orifice 122 and the 3-speed servo release chamber 3S/R is connected to the chamber 52e of the 4-2 sequence valve 52, and the ports 52c and 52f of the 4-2 sequence valve 52 are connected to the first Port 38i of shift valve 38 and second shift valve 40
Connect to port 40h of Port 38j of first shift valve 38 is connected to circuit 125
The port 38d is connected to the port 40d of the second shift valve 40 by the circuit 126, and the port 38d is connected to one inlet port of the shuttle ball 127 by the circuit 126. The other inlet port of shuttle ball 127 is connected to circuit 12.
8 is connected to the port 36R of the manual valve 36 along with the circuit 77 on the one hand, and to the reverse clutch R/C and the accumulator chamber 68d via the one-way orifice 129 on the other hand, and the outlet port of the shuttle pole 127 is connected to the port 36R of the manual valve 36 through the circuit 130. Connect to low reverse brake LR/B.
The port 40j of the second shift valve 40 is connected to the port 54c of the range pressure reducing valve 54 and the chamber 5 by the circuit 131.
4f and the port 54 of the range pressure reducing valve 54.
d is connected to port 36I of manual valve 36 by circuit 132. Port 56e of shuttle valve 56 is connected by circuit 133 to chamber 48e of 3-2 timing valve 48, and port 56d is connected by circuit 134 to chamber 58c of overrun clutch control valve 58. Overrun clutch control valve 58
The port 58d is connected to the accumulator chamber 66d by a circuit 135, and also connected to the accumulator chamber 68e and the 4-speed servo apply chamber 4S/A via a one-way orifice 136. Port 58f of overrun clutch control valve 58 is connected to port 62d of overrun clutch pressure reducing valve 62 by circuit 137, port 62e of pressure reducing valve 62 is connected to overrun clutch OR/C by circuit 137, and port 62e of overrun clutch pressure reducing valve 62 is connected to overrun clutch OR/C by circuit 137. ，
A check valve 139 is provided between 138 and 138. Port 62c of overrun clutch pressure reducing valve 62 is connected to port 36 of manual valve 36 by circuit 140.
and connected to the chamber 56g of the shuttle valve 56. As explained above, in the hydraulic control device of this embodiment, the two duty solenoids 24 and 34 which are duty controlled and the first, second and third shift solenoids which are controlled ON and OFF are used as solenoid valves. 42, 44, and 60 are provided, and each of these solenoid valves is electromagnetically driven according to the vehicle operating condition, thereby controlling the pilot pressure circuit 79a.
Each orifice circuit 81, 97, 100, 10 downstream of the orifice 80, 98, 99, 101, 110 uses the pilot pressure supplied from the
2,109 to generate a signal pressure. By the way, each of these orifice circuits 81, 9
7, 100, 102, and 109 are integrated into a collective circuit 79 via the pilot pressure circuit 79a. In the dust removal mechanism of this embodiment, a strainer 200 is provided in the collective circuit 79, and this strainer 200 is used as a common strainer to connect the pilot valve 26 to each of the orifice circuits 81, 97, 10.
The hydraulic fluid supplied to 0, 102, and 109 is dust-proofed. With the above configuration, in the dust removal mechanism of the hydraulic pressure control device of this embodiment, the common strainer 200 is provided in the collective circuit 79 connected to the pilot valve 26, so that the dust is discharged from the pilot valve 26 as pilot pressure. The working fluid is filtered by the strainer 200, and the dust in the working fluid is removed and the purified working fluid is passed through the pilot pressure circuit 79a to each orifice circuit 81, 97, 100, 102,
109. Therefore,
These orifice circuits 81, 97, 100, 10
2,109, each solenoid valve or duty solenoid 24,3.
4 and first, second, and third shift solenoids 4
2, 44, and 60, and smooth operation is guaranteed. Also, orifice 80,9
Since dust does not adhere to the orifice circuits 8, 99, 101, and 110, the diameter of the orifice is maintained at a predetermined opening area, and together with the smooth operation of the solenoid valve, accurate control pressure is maintained in each orifice circuit 81, 9.
7, 100, 102, and 109, and as a result, appropriate speed change control of the automatic transmission is performed. By the way, in this embodiment, a common strainer 200 is provided in the collective circuit 79 without providing individual strainers in each of the orifice circuits 81, 97, 100, 102, 109. The available space in the valve body can be increased by eliminating the individual strainers. Note that the valve body is a housing that houses the hydraulic pressure control device. In this way, by increasing the exclusive space of the strainer 200, the strainer 200 can be made larger and the passage area of the working fluid can be increased, and clogging of the strainer 200 can be prevented or greatly reduced, and the filtration function can be improved. In addition to trying to improve
By significantly reducing the passage resistance of the hydraulic fluid, accurate pilot pressure can be supplied to the pilot pressure circuit 79a. Effects of the Invention As explained above, in the dust removal mechanism of the hydraulic pressure control device for automatic transmission of the present invention, there is a dust removal mechanism on the downstream side of the pilot valve in a collective circuit of a plurality of orifice circuits in which orifices and solenoid valves are provided. Since a common strainer is provided, the working fluid removed by the strainer can flow into the orifice circuit without causing an increase in suction resistance of the oil pump, unlike when an oil strainer is provided upstream of the oil pump. Not only can the solenoid valve operation and orifice function be maintained normally, but also the number of strainers can be reduced and the number of parts can be reduced.
By increasing the area occupied by the strainer, it is possible to increase the size of the strainer. In other words, by reducing the number of parts, it is possible to simplify assembly work and reduce product costs, and by increasing the size of the strainer, the filtration function is improved and the passage resistance of hydraulic fluid is improved. This has the excellent effect of significantly reducing the amount of

[Brief explanation of the drawing]

Fig. 1 is an overall circuit diagram showing an embodiment of a hydraulic pressure control circuit for an automatic transmission using the dust removal mechanism of the present invention, and Fig. 2 is an automatic transmission to which the hydraulic pressure control device shown in Fig. 1 is applied. A schematic diagram showing one implementation of a power transmission train of
FIG. 3 is a schematic diagram showing the main parts of a conventional dust removal mechanism. 26... Pilot valve, 24, 34... Duty solenoid (solenoid valve), 42...
1st shift solenoid (solenoid valve), 4
4... Second shift solenoid (solenoid valve), 60... Third shift solenoid (solenoid valve), 79... Collective circuit, 80, 98, 9
9,101,110...orifice, 81,9
7,100,102,109...Orifice circuit, 200...Strainer.

Claims (1)

[Scope of utility model registration request] It is equipped with a plurality of orifice circuits into which a common driving fluid pressure regulated to a constant pressure by a pilot valve is introduced through an orifice, and each of these orifice circuits has a solenoid valve installed on the downstream side of the orifice when the vehicle is operating. In a hydraulic pressure control device for an automatic transmission, in which a signal pressure is generated on the downstream side of the orifice of each orifice circuit by being electromagnetically driven according to the A dust removal mechanism for a hydraulic pressure control device for an automatic transmission, characterized in that the orifice circuits are assembled into a collective circuit, and a strainer common to each of the orifice circuits is provided on the downstream side of the pilot valve in the collective circuit.