JPH0241361Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a pressure accumulator for a hydraulic circuit of an automatic transmission widely adopted in vehicles such as passenger cars.

[Prior Art] A hydraulic automatic transmission is widely used as an automatic transmission for automobiles.

In this type of hydraulic automatic transmission, an accumulator is often provided in each hydraulic circuit in order to alleviate the shock when the front clutch, rear clutch, brake, etc. are activated. A pressure accumulator for a hydraulic circuit formed by arranging these accumulators is generally provided on the lower side of the case of a hydraulic automatic transmission, or is formed by attaching a block of a pressure accumulator for a hydraulic circuit to the lower side. has been done.

In the conventional pressure accumulator for the hydraulic circuit of a hydraulic automatic transmission, the back pressure supply port of the accumulator is connected to the second
As shown in the cross-sectional view of an example of a conventional pressure accumulator for hydraulic circuits, three holes A, B, and C are drilled diagonally from the opening of the accumulator cylinder in each accumulator. It was formed by doing.

[Problems to be solved by the invention] However, when forming the back pressure supply port of the accumulator using the method described above, drilling must be performed for each accumulator one by one. The drawback is that the number of machining steps is high and productivity is low. Furthermore, since the hole must be formed diagonally, it is difficult to position the hole during machining, making it difficult to obtain good machining accuracy, and the tip of the drill bit does not touch the side wall of the accumulator cylinder. Since the machining is performed at an angle to the drill, the durability of the drill decreases, and there are problems in that sufficient reliability in machining and forming the back pressure supply port cannot be obtained.

The present invention was developed by focusing on these problems, and it is possible to reduce the number of processing steps to form the back pressure supply port and obtain good productivity. An object of the present invention is to provide a pressure accumulator for a hydraulic circuit of a hydraulic automatic transmission that can obtain sufficient reliability in processing and forming a back pressure supply port by obtaining good processing accuracy and good drill durability. purpose.

[Means for Solving the Problems] The pressure accumulator for a hydraulic circuit of an automatic transmission of the present invention has a large diameter part and a small diameter part, and a plurality of cylinders are provided in parallel and are open on the large diameter part side. a block having a large diameter part and a small diameter part that fit into the large diameter part and the small diameter part of the cylinder, respectively, and which is slidably disposed in each of the cylinders and has an area difference between the large diameter part and the small diameter part. and a plurality of pistons that together with the cylinder constitute a back pressure oil chamber whose pressure receiving surface is a back pressure oil chamber and a hydraulic oil chamber whose pressure receiving surface is the large diameter portion, and the block connects each back pressure oil chamber to the block. Each of the pistons has a back pressure supply port that communicates with the back pressure supply oil passage, and each of the pistons has a first seal member disposed in a small diameter portion of the piston, and The first one has a length equal to or greater than the stroke amount in and the width of the back pressure supply port.
a second seal member disposed on the large diameter portion of the piston at a distance of
from the large diameter side end of the plurality of pistons to the first
a position away from the open end of the cylinder by the minimum value of the second distance to the large diameter side end of the plurality of pistons, and a small diameter of the second seal member from the large diameter side end of the plurality of pistons. between a third distance obtained by adding the stroke amount to the distance to the side end and a position away from the open end of the cylinder by the maximum value;
The block is characterized in that it is formed by machining a single cut hole from the flat end portion of the block and closing the flat end side of the cut hole.

[Operation and Effects of the Invention] In the pressure accumulator for a hydraulic circuit of an automatic transmission of the present invention, the second seal member is connected to the small diameter portion of each of the pistons disposed in each of the plurality of cylinders provided in the block. The first sealing member disposed in is the position away from the open end of the cylinder by the minimum value of the second distance from the large-diameter side end of the plurality of pistons to the large-diameter side end of the first seal member, and the size of the plurality of pistons. and a position away from the open end of the cylinder by the maximum value of a third distance obtained by adding the stroke amount to the distance from the diameter side end to the small diameter side end of the second seal member. Since it is formed by machining a single cut hole from the flat end of the block, the back pressure supply port of each accumulator can be formed with a single cut hole, making it easier to form the back pressure supply port. It is possible to obtain good productivity by reducing the number of machining steps for the cylinder, and since the cut hole can be formed in a direction perpendicular to the cylinder side wall, the machining accuracy of the back pressure supply port can be improved. Since the durability of the drill can be made good, it becomes possible to obtain sufficient reliability in processing and forming the back pressure supply port. Further, the back pressure supply port can be simply configured while maintaining the function of the accumulator, and the pressure accumulator for the hydraulic circuit can be configured compactly.

[Example] The pressure accumulator for the hydraulic circuit of an automatic transmission of the present invention was
An explanation will be given based on an example shown in the figure. FIG. 1 is a cross-sectional view of a pressure accumulator for a hydraulic circuit of an automatic transmission. 1 is a pressure accumulator for the hydraulic circuit installed in the lower part of the case of the hydraulic automatic transmission, and is used for three hydraulic servos such as the clutch or brake of the planetary gear transmission (not shown). It has humulators 3, 4 and 5.

The pressure accumulator block 2 (in this embodiment, it is formed integrally with the case of the automatic transmission) has cylinders 3 of accumulators 3, 4 and 5 arranged in straight parallel.
1, 41 and 51 are provided. cylinder 3
1, 41 and 51 are large diameter portions 311, 411, respectively.
and 511, and small diameter portions 312, 412, and 512, and the large diameter portions 311, 411, and 511 are open. Each of the above cylinders 31, 41
and 51, pistons 32, 42 and 52 are slidably disposed. 33, 43 and 53 are springs attached to the pistons 32, 42 and 52, respectively. The pistons 32, 42, and 52 each have large diameter portions 311, 411, and 511 of the cylinders 31, 41, and 51, and small diameter portions 312,
Large diameter portions 321 that fit into 412 and 512, respectively;
421 and 521 and large diameter portions 322, 422 and 5
22 are provided, and cylinders 31 and 41 are provided, respectively.
and 51 together with large diameter portions 321, 421 and 521
Back pressure oil chambers 31A, 41A and 51A whose pressure receiving surface is the area difference between the small diameter portions 322, 422 and 522.
This constitutes working oil chambers 31B, 41B, and 51B in which the large diameter portions 321, 421, and 521 serve as pressure receiving surfaces. Also, the large diameter portions 321, 421 and 521 of the pistons 32, 42 and 52 and the small diameter portions 322, 4
In order to make the back pressure oil chambers 31A, 41A and 51A and the working oil chambers 31B, 41B and 51B oil-tight, first seal members 323 and 22 and 522 are respectively provided.
423 and 523 and second seal members 324, 42
4 and 524 are provided.

The accumulators 3, 4, and 5 having the above-mentioned configurations include the large diameter portions 32 of the pistons 32, 42, and 52.
Back pressure oil chambers 31A, 41 by setting the diameters of 1,421 and 521 and small diameter portions 322, 422 and 522
A and 51A and working oil chambers 31B, 41B and 51
The pressure receiving area of the hydraulic pressure acting on B, the spring 33,
By appropriately setting the loads 43 and 53 and the stroke amounts S ₃ , S ₄ , and S ₅ in the cylinders 31, 41, and 51 of the pistons 32, 42, and 52, the characteristics required for the hydraulic servo can be obtained. can get.

The block 2 of the pressure accumulator also has a back pressure supply oil passage 6 provided in parallel between the cylinders 31 and 41, and a protrusion 7 protruding from the right side of the cylinder 31 in the figure and having a flat surface 71 at the tip. are doing.

The cylinders 31, 41 and 51 have respective back pressure oil chambers 31A, 41A and 51A and back pressure supply oil passages 6.
are arranged on a straight line substantially perpendicular to the side wall of the cylinder. The cut hole 8 is connected to the central part of the side wall of the cylinders 31, 41 and 51 from the tip flat part 71 of the protruding part 7 and the back pressure supply oil passage 6 which is a round hole.
The back pressure supply port is formed in the direction of arrow D so as to pass perpendicularly across the side wall of the cylinder and communicate the back pressure supply oil passage 6 with these cylinders 31, 41 and 51. . A bolt 9 is a stopper inserted into the cut hole 8 to close the opening on the flat end side of the cut hole 8 in an oil-tight manner.

The back pressure oil chambers 31A, 41A and 51A are connected to the piston 32, when the accumulators 3, 4 and 5 are operated.
42 and 52, and the dimensions of the accumulators 3, 4, and 5 are set according to the characteristics required for each hydraulic servo as described above, so the back pressure oil chambers 31A, 41A and 51
In order to communicate A with one cut hole 8, it is necessary to set the arrangement positions of the second seal members 324, 424 and 524 and the processing position of the cut hole 8 as follows.

The second seal members 324, 424 and 524 are connected to the first seal members 323, 423 and 523, respectively.
From cylinder 3 of pistons 32, 42 and 52
Stroke amounts S ₃ , S ₄ , S ₅ in 1, 41 and 51
The first distances L ₃₁ , L ₄₁ , and L ₅₁ are spaced apart from each other by a length equal to or longer than the width d of the back pressure supply port.

The machining position of the cut hole 8 is from the large diameter side end of the pistons 32, 42 and 52 to the first seal member 32.
A position away from the open end 21 of the cylinder of the block 2 by the minimum value _L 2 of the second distance L ₃₂ , L ₄₂ , L ₅₂ to the end on the large diameter side of the piston 32, 42 and 52 second distance
The length obtained by subtracting the first distance L ₃₁ , L ₄₁ , L ₅₁ from L ₃₂ , L ₄₂ , L ₅₂ , that is, the piston 32, 42
and the second seal member 3 from the large diameter side end of 52.
24, 424 and 524, plus the stroke amounts S ₃ , S ₄ , and S ₅ , which is the maximum distance L ₃ from the open end 21 of the cylinder of block 2. Between. That is, as shown in FIG. 1, the distance from the open end 21 of the cylinder of block 2 is less than L ₂ and L ₃
Machining may be performed so that the cut hole 8 is located within the above range.

The above embodiments are not intended to limit the present invention, and the pressure accumulator block may not be integrally formed with the automatic transmission case, but may be attached as a unit.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a pressure accumulator for a hydraulic circuit of an automatic transmission according to the present invention. FIG. 2 is a sectional view showing a block of a conventional pressure accumulator for a hydraulic circuit. In the figure, 1...Accumulator for hydraulic circuit, 2...Block, 3, 4, 5...Accumulator, 31, 4
1,51...Cylinder, 311,411,511
...Large diameter part of cylinder, 312, 412, 412
...small diameter part of cylinder, 32,42,52...piston, 321,421,521...large diameter part of piston, 322,422,522...small diameter part of piston, 323,423,523...first Seal member, 324, 424, 524...Second seal member, 33, 43, 53...Spring, 31A,
41A, 51A... Back pressure oil chamber, 6... Back pressure supply circuit, 7... Projection, 8... Cut hole (back pressure supply port),
9... Bolt, 71... Flat part.

Claims (1)

[Claims for Utility Model Registration] (1) A block in which a plurality of cylinders having a large diameter part and a small diameter part and opening on the large diameter part side are provided in parallel, and the large diameter part and the small diameter part of the cylinders. a back pressure oil chamber having a large diameter part and a small diameter part which fit into each of the cylinders, and which is slidably disposed in each of the cylinders and has a difference in area between the large diameter part and the small diameter part as a pressure receiving surface; and a plurality of pistons that together with the cylinder constitute a hydraulic oil chamber having a pressure-receiving surface, and the block has a back-pressure supply system that connects each of the back-pressure oil chambers to a back-pressure supply oil path connected to the block. each of the pistons has a first sealing member disposed in a small diameter portion of the piston, and a width of the back pressure supply port is added to the stroke amount of the piston in the cylinder from the first sealing member a second sealing member disposed on the large diameter portion of the piston at a first distance greater than or equal to a length, and the back pressure supply port is located at the large diameter portion side end of the plurality of pistons. a position away from the open end of the cylinder by the minimum value of the second distance from one end of the block from the flat end of the block and a position away from the open end of the cylinder by the maximum value of the third distance obtained by adding the stroke amount to the distance to the end on the small diameter side of the sealing member. 1. A pressure accumulator for a hydraulic circuit of an automatic transmission, characterized in that the pressure accumulator is formed by machining a cut hole and closing the flat end side of the cut hole. (2) The back pressure supply oil passage is arranged in the block in parallel with the cylinder, and the flat end side of the cut hole is closed by fitting a stopper into the cut hole. A pressure accumulator for a hydraulic circuit of an automatic transmission as set forth in claim 1 of the utility model registration claim.