JPH0144824Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) This invention relates to the spring mounting structure.
For example, the present invention relates to a spring mounting structure used in an accumulator for an automatic transmission of a vehicle.

(Prior Art) A plurality of accumulators are incorporated into a hydraulic circuit in an automatic transmission mechanism of an automobile for the purpose of reducing shock during gear shifting. FIG. 3 shows a conventional accumulator. The accumulator AC in the figure is assembled inside the transaxle case 20. The accumulator AC has a spring 21 for movement in the vertical direction in the figure. This spring 21 is housed in a recess 23 formed in the lower part of the accumulator piston 22, and the upper surface of the recess 23 and the case cover 24 are connected to each other.
It is assigned to each.

(Problems to be Solved by the Invention) Therefore, the spring 21 is simply inserted into the recess 23, which may cause the following problems.

That is, since both ends of the spring 23 are only pressed together and not fixed, the spring 21 may tilt as the accumulator piston 22 operates. This happens when,
While scratching the wall surface of the recess 23,
The spring characteristics will change and the original function of the accumulator will be impaired. To improve this problem, a common method is to provide a guide pin or the like on the surface facing the end of the spring 21, and insert one end of the spring 21 into the guide pin to prevent the spring from wobbling.

However, even with this method, if the transaxle case 20 is disassembled for repair, etc., the cover 2
There remains the problem that the spring 21 will fall off when the spring 4 is removed. Furthermore, since the spring 21 is not held when closing the cover 24, it is similarly difficult to close the cover 24.

In view of these problems, the present invention aims to prevent the spring from both axial wobbling and falling off.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a spring mounting structure for mounting an end of a spring made of a compression coil spring in a mounting hole provided in a member to be mounted. An engaging part is formed at the end of the spring and is continuous with the coil and wound so as to have a diameter larger than the coil diameter, and the mounting hole of the attached member has an outer diameter of the engaging part. A tapered surface is formed that has an opening end with a larger diameter and gradually becomes smaller in diameter from the opening end toward the bottom, with the end on the smaller diameter side serving as a throat portion having a smaller diameter than the outer diameter of the engaging portion. Additionally, a fixing groove is formed between the throat portion and the bottom surface of the mounting hole, the groove having a diameter larger than that of the throat portion and in which the engaging portion is engaged with elastic force in the expansion direction. .

(Operation) When mounting the spring on the member to be mounted, the spring is inserted into the mounting hole from the engaging portion side. At this time, as the engaging part of the spring is screwed into the mounting hole, the engaging part is narrowed down while reducing the coil shape by the tapered surface, and by passing over the throat part. It returns elastically and is engaged in the fixing groove with an elastic force in the direction of expansion.

In this manner, the spring is securely fixed to the attached member, so that it is possible to prevent the spring from falling off and prevent shaft wobbling, thereby ensuring smooth operation of the attached member.

(Example) Hereinafter, an example embodying the present invention will be described in detail with reference to the drawings.

FIG. 1 shows one of the accumulators assembled into a transaxle case (hereinafter simply referred to as case 1) of an automobile. The accumulators are housed in a storage section 2 disposed at a suitable location on the outer surface of the case 1, and each is assembled by covering the storage section 2 with a cover 3.

Each accumulator consists of an accumulator piston 4 and a return spring 5.
Note that the spring 5 is made of a compression coil spring.
The accumulator piston 4 is located in the storage section 2.
It is inserted so that it can move in the axial direction. Furthermore, since the accumulator is connected to the hydraulic circuit for the torque converter, oil passages 6 and 7 are open on the top and side surfaces of the accumulator piston 4 on the case 1 side, and the piston opens on the cover 3 side. An oil passage 8 that opens on the lower surface of 4 is formed. The piston 4 is moved up and down by supplying and discharging pressure oil from a predetermined oil path as the gear changes.

On the other hand, one end of the return spring 5 is inserted into a mounting hole 9 formed on the lower surface of the accumulator piston 4, and the other end is placed against the cover 3. The mounting hole 9 is the accumulator piston 4
It is formed coaxially with and has a predetermined depth. Thus, an engaging part 13 is formed at the end of the spring 5, which is continuous with the coil and wound so as to have a diameter larger than the coil diameter. Note that the attachment part 1
3 will be explained in detail later.

Further, a tapered surface 10 is formed in the mounting hole 9 of the accumulator piston 4. The tapered surface 10 has an open end that is larger in diameter than the outer diameter of the engaging portion 13 of the spring 5 (the outer diameter in a free state, dimension A in FIG. 2), and extends from the open end toward the bottom. It gradually becomes a narrow path. The end portion on the small diameter side is defined as a throat portion 11 having a smaller diameter than the outer diameter of the engaging portion 13 (dimension A).

Furthermore, between the throat part 11 and the bottom of the mounting hole 9, that is, on the back side of the throat part 11, there is a circular fixing groove 12 set to a slightly larger diameter (dimension a in the drawing) than this hole diameter (dimension b in the drawing). It is formed in a ring shape.

The above spring 5 has an engaging portion 13 at one end.
is formed so that it can be locked in the fixing groove 12 with elastic force. That is, the engaging portion 13 is formed so that the coil diameter gradually increases in the range of one turn to one and a half turns (see FIG. 2). Further, in this example, the winding direction of the spring 5 is left-handed, and the outer diameter of the engaging portion 13 in the free state (dimension A) is set larger than the diameter of the fixing groove 12 (dimension a). There is. Also, the diameter of the coil inside the engaging part 13 (lower side in the figure) is the throat part 11.
The hole diameter (dimension b) is set to be sufficiently smaller than the hole diameter (dimension b).

Now, in assembling the accumulator, the spring 5 is first attached to the accumulator piston 4. In this case, it is inserted from the engaging part 13 side, but the throat part 1
1, the spring 5 is inserted so as to be screwed in to the right, opposite to the winding direction. By doing so, the engaging portion 13 having a larger diameter than the throat portion 11 is narrowed down by the tapered surface 10 of the mounting hole 9, thereby reducing its diameter and passing through the throat portion 11. When the engaging part 13 is pushed over the throat part 11 and into the fixing groove 12 in this way,
The coil diameter of the engaging part 13 expands due to the elastic return, but as mentioned above, since the diameter of the engaging part 13 in the free state is larger than the diameter of the fixed groove 12, the engaging part 13 expands. 13 engages with the fixing groove 12 with a resilient force in the expansion direction. As a result, the entire spring 5 is attached to the accumulator piston 4 in a state where it is firmly prevented from coming off.

After the above steps, the accumulator piston 4 is inserted into the housing portion 2 and the cover 3 is put on to complete the installation work of the accumulator. When storing the accumulator piston 4, the spring 5 is directed downward, but in this example it is prevented from falling off, so there is no risk of it falling off. Furthermore, regarding the operation of the accumulator after installation, since the engaging portion 13 is fixed, the expansion and contraction of the spring 5 is performed along its axial direction, and there is no axial wobbling. , without damaging the inner wall of the mounting hole 9,
Moreover, the effect that the load characteristics are maintained in a good state can be obtained.

(Effects of the invention) As explained above, according to the invention, the engaging part of the spring is narrowed down while reducing the coil shape by the tapered surface of the mounting hole of the attached member, and it is possible to overcome the throat part. Since the spring returns elastically and is engaged with the fixing groove with a resilient force in the expansion direction, the spring is prevented from falling off and shaft wobbling is also prevented.

In addition, when installing the spring, the engaging part is guided by the tapered surface of the mounting hole of the member to be attached, so it is easy to insert the engaging part into the mounting hole without damaging the engaging part. Can be installed on. In addition, when the spring is compressed, the compressive force acts in the direction of increasing the diameter of the engaging part, increasing the elastic force in the expanding direction of the engaging part with respect to the fixing groove. The effect that the attachment of the attachment portion to the attachment portion becomes stronger and displacement of the attachment position is prevented is also recognized.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view of a spring mounting structure in this example, FIG. 2 is a plan view of the spring, and FIG. 3 is a partially cutaway front view of a conventional spring mounting structure. 4...Accumulator piston, 5...Spring, 9...Mounting hole, 11...Throat part, 1
2... Fixing groove, 13... Engaging portion.

Claims (1)

[Scope of utility model registration request] In a spring mounting structure for mounting the end of a spring made of a compression coil spring in a mounting hole provided in a member to be mounted, the end of the spring is connected to the coil and has a diameter larger than the coil diameter. forming a wound engagement part;
The attachment hole of the attached member has an open end having a larger diameter than the outer diameter of the engaging portion, and the diameter gradually decreases from the open end toward the bottom, and the small diameter side end is connected to the engaging portion. A tapered surface is formed with a throat portion having a smaller diameter than the outer diameter of the
A fixing groove is formed between the throat portion and the bottom surface of the mounting hole, the groove having a diameter larger than that of the throat portion and to which the engaging portion is engaged with elastic force in the expansion direction. Spring mounting structure.