JPS6323620Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a hydraulic shock absorber used for vibration prevention in vehicles or industrial equipment.

Conventional hydraulic shock absorbers of this type have a piston that is slidably fitted into a cylinder, and a flow path that communicates between an upper chamber of the piston and a lower chamber of the piston, and the flow of oil in this flow path. It is known that the valve is controlled by a disc valve biased toward the piston by a disc spring.

However, this hydraulic shock absorber has the following problems in the manufacturing process. That is, when manufacturing this hydraulic shock absorber, a washer is first fitted into the small diameter portion formed at the tip of the piston rod, then a disc spring is inserted, and then an annular retainer is installed to ensure the amount of deflection of the disc spring. Then, insert a disk valve that fits into the outer periphery of this retainer, then insert a piston and a valve, and tighten the whole thing with a nut from the tip of the piston rod. Here, in the conventional type, when the disc valve is inserted, the valve does not fit into the outer periphery of the retainer, resulting in a situation where the retainer and the disc valve overlap, and if the disc valve is tightened with a nut in this state, the disc valve A situation occurs in which the retainer is caught between the retainer and the piston.

Therefore, this invention provides a hydraulic shock absorber in which there is no risk of the disc valve being caught between the retainer and the piston during manufacturing.
A piston having a piston rod fixed to the center thereof is inserted into the cylinder, a flow path communicating between an upper piston chamber and a lower piston chamber is provided in the piston, and one of the pistons in the piston upper chamber is provided with a flow path communicating between the piston upper chamber and the piston lower chamber. In the hydraulic shock absorber, a valve mechanism for controlling the flow of oil in the flow path is provided between the surface and a step formed in the middle of the piston rod, the inner peripheral edge of which is fitted to the piston rod. , an annular retainer that abuts one surface of the piston, a disc valve whose inner peripheral edge is fitted into the retainer and moves toward and away from one surface of the piston, and a stepped portion of the retainer and the piston rod. a disk spring whose inner circumferential side is held between and whose outer circumferential side biases the disc valve toward one surface of the piston; The valve mechanism includes a retainer holding spring that biases the retainer toward one surface of the piston.

An embodiment of this invention will be described below with reference to the drawings. FIG. 1 and FIG. 2 are sectional views showing the configuration of the main parts of the hydraulic shock absorber according to this invention, respectively.
Figure 1 is a diagram showing the state in the middle of manufacturing, and
FIG. 2 is a diagram showing the state at the time of completion. In these figures, reference numeral 1 denotes a cylinder, and a piston 2 is slidably fitted inside the cylinder 1, and the inside of the cylinder 1 is divided into an upper piston chamber 3 and a lower piston chamber 4. It is divided into two parts. Annular grooves 5 and 6 are formed on the upper and lower surfaces of the piston 2, respectively.
A flow path 8 communicating between the upper surface periphery and the groove 6 and a flow path 9 communicating between the lower surface periphery and the groove 5 are formed in the . Next, code 10
is a piston rod. This piston rod 1
A small diameter portion 10a is formed at the tip of the spring 10, a washer 11 is inserted into the small diameter portion 10a, a disc spring 12 is inserted, and an annular retainer 13 is inserted to ensure the amount of deflection of the disc spring 12. inserted,
Next, the disc valve 14 is fitted around the outer periphery of this retainer 13, then the above-mentioned piston 2 is inserted, then the pressure reducing valve 15 is inserted, then the retainer 16 is inserted, then the washer 17 is inserted, and then the nut 18 is inserted. Each of the above-mentioned parts is tightened and fixed by. In addition, this nut 1
8, the inner circumferential side of the disc spring 12 is pressed from the upper side in the figure by the stepped portion 10b formed on the piston rod 10 via the washer 11. There is.

Here, the disc spring 12 has a mounting part 12a having a hole in the center as shown in FIG.
Six legs 12b, 12b extending radially from a
..., and each leg portion 12b, 12b... is bent at a predetermined angle in the same direction with respect to a plane including the mounting portion 12a (see FIG. 3B). Furthermore, bent portions 12c, 12c, and 12c (biasing members) that protrude in the same direction as the leg portions 12b are formed on the inner peripheral edge of the attachment portion 12a. The mounting portion 12a is then held between the retainer 13 and the washer 11. The disc valve 14 is constituted by an annular plate, and is pressed against the upper surface of the groove 5 by a disc spring 12. The pressure reducing valve 15 is a valve made of an elastic material, and controls opening and closing between the groove 6 and the lower piston chamber. Note that in the above-described configuration, the disc spring 12, the retainer 13, and the disc valve 14 constitute the valve mechanism 20.

Therefore, in Fig. 2, the piston rod 10
When the piston moves upward, the pressure of the oil in the piston upper chamber 3 increases. As a result, the disc valve 14
is in the closed state, while the outer peripheral portion of the pressure reducing valve 15 is bent downward, and the oil in the piston upper chamber 3 flows into the piston lower chamber 4 through the flow path 8 and the groove 6. on the other hand,
When the piston rod 10 moves downward, the pressure of the oil in the lower piston chamber 4 increases. This results in
While the pressure reducing valve 15 is closed, the disc valve 14 moves upward against the biasing force of the disc spring 12, and the oil in the piston lower chamber 4 flows into the piston upper chamber 3 through the flow path 9 and the groove 5. Inflow. The above-mentioned resistance to movement of oil between the piston upper chamber 3 and the piston lower chamber 4 acts as a damping force.

Next, the manufacturing process of the above-mentioned hydraulic shock absorber will be explained. First, the piston rod 10 and cylinder 1 are turned upside down (upside down from the case shown in FIG. 1), and the washer 11, disc spring 12, retainer 13, and disc valve 14 are sequentially inserted into the small diameter portion 10a. In the above embodiment, since the bent portion 12c is formed in the disc spring 12, the tip of the leg part 12b of the disc spring 12 is located above the end surface 13a of the retainer 13 in the figure, as shown in FIG. 4A. As a result, when the disc valve 14 is inserted, the disc valve 14 fits into the outer periphery of the retainer 13. On the other hand, the bent portion 1 is attached to the disc spring 12.
2c is not formed, as shown in FIG.
Do not fit into the outer periphery of the Therefore, in this state, if the piston 2 etc. are further inserted into the small diameter portion 10a of the piston rod 10 and tightened with the nut 18, the disc valve 14 will be caught between the retainer 13 and the piston 2.

Now, after inserting the disc valve 14 into the small diameter portion 10a and fitting it around the outer periphery of the retainer 13, the piston 2, pressure reducing valve 15, retainer 16, washer 17
are sequentially inserted into the small diameter portion 10a, and then the nut 1
Tighten with 8. As a result, the bent portion 12c of the disc spring 12 becomes flush with the mounting portion 12a, and the state shown in FIG. 2 is completed. Note that the biasing force of the disc spring 12 has a magnitude corresponding to the amount of deflection of the bent portion 12c (see symbol t in FIG. 1).

Next, another example of the configuration of the disc spring 12 is shown in FIG. This disk spring 12' has six bent portions 12d, 12d, . . . formed on the inner peripheral edge of the mounting portion 12'a. This disc spring 12' is a disc spring 12 shown in FIG.
When the legs 12'b, 12'b, . . . are fixed at the position shown in FIG.

In addition, in the embodiment shown in FIGS. 1 and 2, the bent portion 12c is formed on the disc spring 12, but
Instead, a biasing member such as a spring washer may be inserted between the conventional disc spring (see FIG. 4B) and the retainer 13.

As explained above, according to this invention, since the retainer holding spring that biases the retainer toward the piston is provided, it is possible to prevent the disc valve from being caught between the retainer and the piston during manufacturing. In addition, this invention has the advantage that the outer diameter of the valve mechanism is smaller and the number of parts can be reduced compared to the conventional one using coil springs. There are also benefits that can be used.

[Brief explanation of drawings]

1 and 2 are cross-sectional views showing the configuration of the main parts of a hydraulic shock absorber 9 according to an embodiment of the invention, with FIG. 1 showing a state in the middle of manufacturing, and FIG. 3A is a plan view showing the configuration of the disc spring 12 in FIG. 1, B is a sectional view taken along line A-A in FIG. 5A is a plan view showing another configuration example of the disc spring 12, and FIG.
FIG. DESCRIPTION OF SYMBOLS 1... Cylinder, 2... Piston, 3... Piston upper chamber, 4... Piston lower chamber, 9... Channel, 10... Piston rod, 10b... Step part of piston rod, 12
... Disc spring, 12c... Bent part, 13... Retainer,
14...Disc valve, 20...Valve mechanism.

Claims (1)

[Scope of utility model registration request] A piston with a piston rod fixed to the center is inserted into the cylinder, and this piston has a
A flow path communicating between the piston upper chamber and the piston lower chamber is provided, and a flow path is provided between one surface of the piston in the piston upper chamber and a step formed in the middle of the piston rod. A hydraulic shock absorber is provided with a valve mechanism for controlling the flow of oil, and the valve mechanism includes an annular retainer whose inner peripheral edge is fitted into the piston rod and abuts one surface of the piston; A disk valve whose inner circumferential edge is fitted into and moves toward and away from one surface of the piston, whose inner circumferential side is held between the retainer and the stepped portion of the piston rod, and whose outer circumferential side is held by the disk valve. A disc spring that biases the valve toward one surface of the piston; and a retainer holding spring that is integrally provided on the inner peripheral side of the disc spring and biases the retainer toward one surface of the piston. A hydraulic shock absorber comprising: