Engine brake rocker arm with accurate stroke

Abstract

The utility model discloses an engine brake rocker arm with an accurate stroke. The engine brake rocker arm comprises a rocker arm body, the upper end part of the threaded rod is fixedly connected to the rocker arm body; a mounting cavity is formed in the piston body, the upper end face of the piston body is open, and the lower end of the threaded rod is arranged in the piston body in a penetrating mode; the limiting cap is arranged on the threaded rod in a sleeving mode, at least part of the limiting cap is located in the piston body, and the threaded rod is prevented from disengaging from the piston body; the locking ring is arranged on the limiting cap in a sleeving mode and located in the piston body, the inner diameter of the locking ring is smaller than the maximum outer diameter of the limiting cap, and the maximum outer diameter of the locking ring is larger than the inner diameter of the opening in the upper end of the piston body; and the spring is arranged on the threaded rod in a sleeving mode and compressed between the limiting cap and the lower end of the threaded rod, and the spring enables the threaded rod to have the tendency of being away from the limiting cap from top to bottom all the time. The piston is accurate in stroke, simple in structure, convenient to install and low in machining cost.

Description

Technical Field

[0001] The utility model relates to an engine brake rocker arm with precise stroke. Background Art

[0002] Engine brakes achieve their braking function by pushing the engine valves open or closed. Generally, there are multiple methods for achieving this action, suitable for different engine brake installation methods. Currently, most engine brakes are fixed or swing-type, and both types of engine brakes essentially achieve the valve pushing action through a single piston assembly. However, since the pistons used in fixed brakes don't factor in angle variation, they are difficult to use in swing-type engine brakes. To achieve precise travel, too many adapter kits are required, resulting in high costs. Summary of the Invention

[0003] The utility model aims to provide an engine brake rocker arm with a precise stroke, wherein the piston of the rocker arm can accurately extend and retract to realize the opening action of pushing the engine valve.

[0004] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a precise stroke engine brake rocker arm, which includes a rocker arm body and a piston mounted on the rocker arm, wherein the piston includes:

[0005] A threaded rod, the upper end of which is fixedly connected to the rocker arm body;

[0006] A piston body, which has an installation cavity formed therein and an open upper end surface, and the lower end of the threaded rod is inserted into the piston body;

[0007] a limiting cap, which is sleeved on the threaded rod and at least partially located in the piston body and limits the threaded rod from coming out of the piston body;

[0008] a locking ring, which is sleeved on the limiting cap and located in the piston body, wherein the inner diameter of the locking ring is smaller than the maximum outer diameter of the limiting cap, and the maximum outer diameter of the locking ring is larger than the inner diameter of the open upper end of the piston body;

[0009] A spring is sleeved on the threaded rod and compressed between the limiting cap and the lower end of the threaded rod. The spring makes the threaded rod always tend to move away from the limiting cap from top to bottom.

[0010] In another embodiment, a thread is provided on the circumferential surface of the upper end portion of the threaded rod, and the major diameter of the thread is loosely matched with the inner diameter of the limiting cap.

[0011] In another embodiment, a first boss and a second boss located below the first boss are provided on the lower end portion of the threaded rod. The diameter of the first boss is larger than the inner diameter of the through hole of the limiting cap, thereby serving as a stroke limiter.

[0012] In another embodiment, the diameter of the second boss is larger than the outer diameter of the spring, and the lower end of the spring abuts against the upper end surface of the second boss.

[0013] In another embodiment, the locking ring is an elastic element, and its diameter can be increased or decreased in the radial direction under the action of external force. When its diameter becomes minimum, its outer diameter is larger than the inner diameter of the upper opening of the piston body.

[0014] In another embodiment, the inner wall of the piston body is provided with an inner step, and an annular third boss is formed on the outer peripheral surface of the lower end of the limiting cap. When the spring is in a natural state, the lower end surface of the third boss is pressed on the upper end surface of the inner step.

[0015] In another embodiment, the inner wall of the piston body is provided with an annular groove located above the inner step, and the locking ring is arranged in the annular groove.

[0016] Due to the application of the above technical solution, the utility model has the following advantages compared with the existing technology: the utility model designs a single-sided limiting structure for the engine brake that swings with the rocker arm axis as the swing center, and uses the piston contact surface matched with this structure to accurately promote the opening of the engine valve; the piston stroke is accurate, the structure is simple, the installation is convenient, and the processing cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural diagram of the utility model;

[0018] Figure 2 A cross-sectional view of the piston of the present utility model;

[0019] Figure 3 This is an exploded view of the piston of the present invention. DETAILED DESCRIPTION

[0020] like Figure 1-3 As shown, the engine brake rocker arm with precise stroke includes a rocker arm body 0, a piston 9 installed on the rocker arm, and the piston 9 includes: a threaded rod 1, a piston body 2, a limiting cap 3, a locking ring 4 and a spring 5.

[0021] The upper end of the threaded rod 1 is fixedly connected to the rocker arm body 0 by a thread and reinforced with a nut 8; specifically, a thread is provided on the circumferential surface of the upper end of the threaded rod 1, and the major diameter of the thread is clearance-matched with the inner diameter of the limiting cap 3; the lower end of the threaded rod 1 is provided with a first boss 11 and a second boss 12 located below the first boss 11, the diameter of the first boss 11 is larger than the inner diameter of the through hole of the limiting cap 3, and plays the role of stroke limiting; the diameter of the second boss 12 is larger than the outer diameter of the spring 5, and the lower end of the spring 5 rests on the upper end surface of the second boss 12.

[0022] An installation cavity is provided inside the piston body 2 and the upper end surface is open. The lower end of the threaded rod 1 is passed through the piston body 2; the inner wall of the piston body 2 is provided with an inner step 21, and the inner wall of the piston body 2 is provided with an annular groove 22 located above the inner step 21, and the locking ring 4 is provided in the annular groove 22.

[0023] The limiting cap 3 is sleeved on the threaded rod 1 and has at least a part located in the piston body 2 and limits the threaded rod 1 from escaping from the piston body 2; an annular third boss 31 is formed on the outer peripheral surface of the lower end portion of the limiting cap 3, and the upper end surface of the third boss 31 extends downward in an arc shape. When the spring 5 is in a natural state, the lower end surface of the third boss 31 is pressed on the upper end surface of the inner step 21; the lower surface of the limiting cap 3 contacts the bottom surface of the inner step 21 of the piston body 2, the third boss 31 of the limiting cap 3 contacts the inner diameter surface of the locking ring 4, and the outer diameter surface of the locking ring 4 contacts the upper groove surface of the ring groove of the piston body 2, but not the lower groove surface.

[0024] The locking ring 4 is sleeved on the limiting cap 3 and located within the piston body 2. The inner diameter of the locking ring 4 is smaller than the maximum outer diameter of the limiting cap 3, and the maximum outer diameter of the locking ring 4 is larger than the inner diameter of the upper opening of the piston body 2. The locking ring 4 is an elastic element, and its diameter can be increased or decreased in the radial direction under the action of external force. When its diameter is reduced to the minimum, its outer diameter is larger than the inner diameter of the upper opening of the piston body 2. Due to the elastic characteristics of the locking ring 4, this contact state can enable the ring groove, the locking ring 4 and the limiting cap 3 to achieve the function of automatic adjustment, thereby increasing the accuracy of the stroke. At the same time, because this contact state can eliminate the cumulative tolerance of the relevant dimensions of the threaded rod 1, the limiting cap 3 and the piston body 2 to a certain extent, this design has a shorter dimensional chain, reduces the precision requirements for a single dimension, and thus reduces the manufacturing cost of the piston.

[0025] The spring 5 is sleeved on the threaded rod 1 and compressed between the limiting cap 3 and the lower end of the threaded rod 1. The spring 5 makes the threaded rod 1 always tend to move away from the limiting cap 3 from top to bottom.

[0026] Of course, on the other hand, the piston stroke is also related to the height of the first boss 11 of the threaded rod 1. When the spring 5 is installed, the lower bottom surface of the spring 5 contacts the second boss 12 of the threaded rod 1, and the upper end surface of the spring 5 contacts the lower end surface of the third boss 31 of the limiting cap. Due to the tension of the spring 5, the stroke of the piston body 2 is zero. When an external force acts on the upper end surface of the piston body 2, the piston body 2 will move downward; when the external force is greater than the spring 5 force of the spring 5 at a given stroke, the lower end surface of the limiting cap 3 will contact the upper end surface of the first boss 11 of the threaded rod 1, thereby reaching the maximum stroke. In this process, the annular groove, the locking ring 4 and the limiting cap 3 are always in contact, and the piston stroke is naturally guaranteed.

[0027] In addition, in view of the application scenario of the swing installation, the shape of the bottom of the piston body 2 is also designed according to the swing angle requirements and the shape of the corresponding contact surface, so as to control the movement range of the contact point and realize the stroke control of the contacted part.

[0028] The above embodiments are intended only to illustrate the technical concepts and features of the present invention. Their purpose is to enable those familiar with the art to understand the contents of the present invention and implement them accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent changes or modifications based on the spirit of the present invention are intended to be included in the scope of protection of the present invention.

Claims

1. A precise stroke engine brake rocker arm, comprising a rocker arm body and a piston mounted on the rocker arm, characterized in that: The piston comprises: A threaded rod, the upper end of which is fixedly connected to the rocker arm body; A piston body, which has an installation cavity formed therein and an open upper end surface, and the lower end of the threaded rod is inserted into the piston body; a limiting cap, which is sleeved on the threaded rod and at least partially located in the piston body and limits the threaded rod from coming out of the piston body; a locking ring, which is sleeved on the limiting cap and located in the piston body, wherein the inner diameter of the locking ring is smaller than the maximum outer diameter of the limiting cap, and the maximum outer diameter of the locking ring is larger than the inner diameter of the open upper end of the piston body; A spring is sleeved on the threaded rod and compressed between the limiting cap and the lower end of the threaded rod. The spring makes the threaded rod always tend to move away from the limiting cap from top to bottom.

2. The precise travel engine brake rocker arm according to claim 1, characterized in that: A thread is provided on the circumferential surface of the upper end portion of the threaded rod, and the major diameter of the thread is clearance-matched with the inner diameter of the limiting cap.

3. The precise travel engine brake rocker arm according to claim 1, characterized in that: A first boss and a second boss located below the first boss are provided on the lower end portion of the threaded rod, and the diameter of the first boss is larger than the inner diameter of the through hole of the limiting cap.

4. The precise travel engine brake rocker arm according to claim 3, characterized in that: The diameter of the second boss is larger than the outer diameter of the spring, and the lower end of the spring abuts against the upper end surface of the second boss.

5. The precise travel engine brake rocker arm according to claim 1, characterized in that: The locking ring is an elastic element, and its diameter can be increased or decreased in the radial direction under the action of external force. When its diameter becomes minimum, its outer diameter is larger than the inner diameter of the upper opening of the piston body.

6. The precise travel engine brake rocker arm according to claim 3, characterized in that: The inner wall of the piston body is provided with an inner step, and an annular third boss is formed on the outer peripheral surface of the lower end of the limiting cap. When the spring is in a natural state, the lower end surface of the third boss is pressed on the upper end surface of the inner step.

7. The precise travel engine brake rocker arm according to claim 6, characterized in that: The inner wall of the piston body is provided with an annular groove located above the inner step, and the locking ring is arranged in the annular groove.

Images