JPH0519630Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to an upper end cap mounting structure of a hydraulic shock absorber, and in particular, a hydraulic shock absorber that improves the durability of the upper end cap mounting portion disposed on the outer periphery of the upper end of a piston rod. Concerning the upper end cap mounting structure of the device.

[Prior Art] As an upper end cap mounting structure of a hydraulic shock absorber, there is a structure as shown in FIG. 2, which has been proposed in the past.

That is, in the hydraulic shock absorber, a piston rod 2 is inserted into a cylinder 1, and a suspension spring 3 is interposed between the cylinder 1 and the piston rod 2.
In addition, a lower end bracket 1a is attached to the lower end of the cylinder 1, and an upper end bracket 2 is attached to the upper end of the piston rod 2.
It has a.

The lower end of the suspension spring 3 is locked to a lower spring receiver 3a fixed to the outer periphery of the cylinder 1, and the upper end is engaged with the lower end of an upper end cap 4 interposed on the outer periphery of the upper end of the piston rod 2. It is locked to.

Furthermore, the inner circumferential side of the upper end cap 4 is interposed in the narrow diameter portion 2b that is the upper end of the piston rod 2, and the above-mentioned upper end bracket 2a is fixed to the upper end of the narrow diameter portion 2b by welding. .

Therefore, the repulsive force of the suspension spring 3 is
The force is transmitted to the upper end cap 4 via the piston rod 2, thereby energizing the piston rod 2 to rise.

[Problems to be solved by the invention] However, when the repulsive force of the suspension spring 3 acts eccentrically in the axial direction, which is the biasing direction,
Stress will be concentrated on the upper end narrow diameter part 2b of the piston rod 2, but since the upper end bracket 2a is fixed to the upper end narrow diameter part 2b of the piston rod 2 by welding, it may become weakened there. There is a risk that the eccentric repulsion force causes cracks in the narrow diameter portion of the upper end of the piston rod 2, resulting in a reduction in durability.

[Purpose of the invention] In view of the above-mentioned circumstances, the present invention has been devised to provide a hydraulic shock absorber that can stably lock the upper end of the suspension spring without causing the upper end of the piston rod to become weakened in the future. The purpose is to provide a new upper end cap mounting structure.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention has a structure in which a piston rod is inserted into a cylinder, an upper end bracket such as an eye is welded to the upper end of the piston rod, and an upper end bracket such as an eye is welded to the upper end of the piston rod. In a hydraulic shock absorber, an upper end cap is provided at the piston rod, and a suspension spring is interposed between an upper spring support provided at the lower end of the upper end cap and a lower spring support provided on the outer periphery of the cylinder. It consists of a pipe-shaped press-fitting part into which the columnar upper end is inserted, and an expanding part formed below the press-fitting part, and the upper end surface of the press-fitting part and the upper end surface of the piston rod are located on the same plane, and the above-mentioned It is characterized in that the upper end bracket is welded to the upper end surface of the press-fitting part and the upper end surface of the piston rod.

[Example] The present invention will be described below based on the illustrated example.

FIG. 1 shows a hydraulic shock absorber according to a preferred embodiment of the present invention, in which a piston rod 12 is inserted into a cylinder 11, and there is a space between the piston rod 12 and the cylinder 11. A suspension spring 13 is interposed. A lower end bracket 11a is fixed to the lower end of the cylinder 11, and an upper end bracket 12a such as an eye is fixed to the upper end of the piston rod 12 by welding. And also, the lower end bracket 11
For example, the upper end bracket 12a is connected between the axles of a vehicle, and the upper end bracket 12a is connected to the vehicle body side of the vehicle. The force is used to raise the piston rod 12.

The suspension spring 13 has its lower end secured to a lower spring receiver 13a fixed to the outer peripheral surface of the cylinder 11, and its upper end secured to an upper spring receiver 13b disposed on the piston rod 12 side. A seat member 13c is interposed between the lower spring receiver 13a and the lower end of the suspension spring 13, and a spacer 13d is interposed between the upper spring receiver 13b and the upper end of the suspension spring 13. ing. Note that the spacer 13d is formed to be long so as to also serve as a cover for protecting the sliding portion between the cylinder 11 and the piston rod 12 from the outside, but instead of this, the suspension spring 13 is made long, and , lower seat member 13
Of course, it may be formed into a short length as shown in c.

The upper spring receiver 13b is attached to the piston rod 12
It is locked to the lower end of an upper end cap 14 interposed on the outer periphery of the upper end. Then, the cap 14
The piston rod 12 has a press-fitting portion 14a that allows the outer periphery of the upper end of the piston rod 12 to be press-fitted therein. The press-fitting portion 14a is formed into a pipe shape with an appropriate length so as to be pressed against the outer periphery of the upper end of the piston rod 12. And also, the press-fitting part 1
The inner diameter of the piston rod 4a is formed to match the cylindrical outer diameter of the upper end of the piston rod 12.

In addition, in the upper end cap 14, a widening part 14b is formed below the press-fitting part 14a, and a cushion rubber 15 is mounted inside the widening part 14b. The upper spring receiver 13b is located at the lower end of the expanded portion 14b.

[Effect of the idea] According to the present invention, there are the following effects.

The upper end of the piston rod is formed into a cylindrical shape without a narrow diameter part, and the pipe-shaped press-fit part of the upper end cap is press-fitted into the outer periphery of the upper end of the piston rod, so the upper end of the piston rod is reinforced and its weakening is prevented. This will prevent you from being invited.

As mentioned above, the upper end cap is supported along the outer circumference of the piston rod through the pipe-shaped press-fitted part, so it is always held concentrically with the piston rod, and even if the repulsive force of the suspension spring acts eccentrically, There is no slope.

The upper end surface of the press-fit part and the upper end surface of the cylindrical upper end of the piston rod are located on the same plane, and since the upper end bracket such as an eye is welded to the upper end surface of the piston rod and the upper end surface of the press-fit part, the area for welding is It is large and allows for strong welding of the upper end bracket.

Even if the repulsive force from the suspension spring eccentrically acts on the upper end cap, since the press-fitted part is long and pipe-shaped, the stress will not be concentrated in one place, improving the durability of the piston rod and the upper end cap.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway front view showing an embodiment of the present invention, and FIG. 2 is a partially cutaway front view showing a conventional example. 11...Cylinder, 12...Piston rod,
12a... Upper end bracket, 13... Suspension spring,
13a...Lower spring holder, 13b...Upper spring holder,
14... Upper end cap, 14a... Press-fitting part, 14
b... Expansion part.

Claims (1)

[Scope of utility model registration request] In a hydraulic shock absorber in which a piston rod is inserted into a cylinder, an upper end bracket such as an eye is welded to the upper end of the piston rod, an upper end cap is further provided at the upper end of the piston rod, and a suspension spring is interposed between an upper spring bearing provided at the lower end of the upper end cap and a lower spring bearing provided on the outer periphery of the cylinder, the upper end cap comprises a pipe-shaped press-fit portion through which the cylindrical upper end of the piston rod is inserted and an expanded portion formed below the press-fit portion, the upper end surface of the press-fit portion and the upper end surface of the piston rod are positioned on the same plane, and the upper end bracket is welded to the upper end surface of the press-fit portion and the upper end surface of the piston rod.