Compression release brake rocker arm assembly and engine

Abstract

The utility model relates to the technical field of engine braking, in particular to a compression release braking rocker arm assembly and an engine. The rocker arm assembly comprises a rocker arm body, an executing mechanism and an exhaust mechanism. The executing mechanism and the exhaust mechanism are arranged on the rocker arm body and communicated through an oil way. The exhaust mechanism comprises an adjusting screw, a movable pin and an elephant foot, the movable pin is inserted into the adjusting screw, a first oil discharging way is arranged on the side wall of the adjusting screw, a second oil discharging way is arranged at the end of the adjusting screw, a third oil discharging way is arranged on the side wall of the movable pin, and the elephant foot can push the movable pin to move relative to the adjusting screw. And the first oil unloading path, the second oil unloading path and the third oil unloading path are communicated. The oil discharge path of an existing brake rocker arm is changed, and a new matching structure does not need to be additionally arranged outside the brake rocker arm.

Description

Technical Field

[0001] The utility model relates to the technical field of engine braking, in particular to a compression-release braking rocker arm assembly and an engine. Background Art

[0002] During a long downhill slope, the vehicle needs to continue to brake to stabilize the driving speed. Long-term braking will cause the brake pads to overheat, affecting the reliability and service life of the brake pads. Rocker arm braking is a technology that achieves in-cylinder braking by opening the exhaust valve bridge in advance or delaying.

[0003] The prior art (publication number CN114033525A) discloses a brake rocker arm, a brake rocker arm system and a vehicle, which can realize the braking function under the action of hydraulic pressure by only arranging a piston and an elastic member on the rocker arm body. The reset process of the brake rocker arm structure is to return the hydraulic oil of the one-way valve, so it is necessary to add a base at the position corresponding to the one-way valve of the brake rocker arm, which is complex in structure. Utility Model Content

[0004] In view of the deficiencies in the prior art, an object of the embodiments of the utility model is to provide a compression-release brake rocker arm assembly, which changes the oil unloading path of the existing brake rocker arm without adding a new matching structure outside the brake rocker arm.

[0005] In order to achieve the above purpose, the embodiment of the utility model provides the following technical solutions:

[0006] A compression-release brake rocker arm assembly comprises: a rocker arm body, an actuator and an exhaust mechanism, wherein the actuator and the exhaust mechanism are arranged on the rocker arm body and are connected through an oil circuit; the exhaust mechanism comprises an adjusting screw, a movable pin and an elephant foot, wherein the movable pin is inserted into the adjusting screw, a first oil discharge circuit is arranged on the side wall of the adjusting screw, a second oil discharge circuit is arranged at the end, a third oil discharge circuit is arranged on the side wall of the movable pin, and the elephant foot can push the movable pin to move relative to the adjusting screw, so that the first oil discharge circuit, the second oil discharge circuit and the third oil discharge circuit are connected.

[0007] Optionally, a one-way valve is also included, and a rocker arm shaft cavity is provided on the rocker arm body. The one-way valve, actuator and exhaust mechanism are arranged on the rocker arm body in sequence, and the distances from the one-way valve, actuator and exhaust mechanism to the rocker arm shaft cavity increase in sequence, and the two closest ones of the one-way valve, actuator and exhaust mechanism are connected through an oil circuit.

[0008] Optionally, the rocker arm shaft cavity is connected to a one-way valve through a first brake oil circuit, and the one-way valve is connected to the actuator through a second brake oil circuit, and the one-way valve realizes one-way conduction from the first brake oil circuit to the second brake oil circuit.

[0009] Optionally, the one-way valve includes a screw plug, a one-way spring and a steel ball, and has a conical hole on the rocker arm body, one end of the conical hole is connected to the first brake oil circuit, and the other end is connected to the oil chamber in the one-way valve, and the oil chamber in the one-way valve is connected to the second brake oil circuit, and the steel ball is against one end of the conical hole facing the oil chamber, one end of the one-way spring is against the steel ball, and the other end is against the screw plug.

[0010] Optionally, the actuator is connected to the exhaust mechanism via an unloading oil circuit, a brake chamber is provided in the actuator, and the second brake oil circuit and the unloading oil circuit are both connected to the brake chamber.

[0011] Optionally, the actuator includes a brake screw, a brake spring, a brake piston and a spring seat; the spring seat is sleeved on the brake screw, the brake piston is sleeved on the end of the brake screw, and one end of the brake piston is clamped with the spring seat, one end of the brake spring is against the spring seat, and the other end is against the brake screw.

[0012] Optionally, the brake piston and the spring seat are clamped together by a clamp.

[0013] Optionally, the elephant foot is slidably mounted on the rocker arm body, one end of the elephant foot is used to crimp the valve bridge, the other end of the elephant foot has a blind hole, a first spring is installed in the blind hole, one end of the first spring abuts against the elephant foot, and the other end abuts against the adjusting screw.

[0014] Optionally, the exhaust mechanism also includes a spring sleeve, which is installed on the end of the adjusting screw, and the movable pin is inserted into the spring sleeve. A second spring is arranged between the adjusting screw and the movable pin, and the second spring has a tendency to make one end of the movable pin protrude out of the spring sleeve.

[0015] An embodiment of the utility model further provides an engine, comprising the compression-release brake rocker arm assembly as described above.

[0016] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0017] In the brake rocker arm assembly of the utility model, a movable pin and an oil unloading path are added in the exhaust mechanism. When the elephant foot rises under the reaction of the valve bridge, the movable pin is compressed to move relative to the adjustment screw, so that the first oil unloading path on the adjustment screw, the third oil unloading path on the movable pin and the second oil unloading path on the adjustment screw form a conductive oil unloading path for oil unloading. That is, the brake oil is unloaded through the execution structure instead of flowing back through the one-way valve, and the oil unloading process is realized by the rocker arm assembly cooperating with the existing structure (valve bridge, elephant foot), without adding a matching structure such as a base, and the structure is simple.

[0018] Additional advantages of the present invention will be given in the following description, and some will become apparent from the following description or will be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention.

[0020] Figure 1 It is a schematic diagram of a brake rocker arm assembly provided by an embodiment of the utility model;

[0021] Figure 2 It is a schematic diagram of the rocker arm shaft cavity of the rocker arm body provided by the embodiment of the utility model;

[0022] Figure 3 It is a schematic diagram of the inside of a one-way valve provided in an embodiment of the utility model;

[0023] Figure 4 It is a schematic diagram of the interior of the actuator provided by the embodiment of the utility model;

[0024] Figure 5 This is a schematic diagram of the exhaust mechanism provided by the embodiment of the utility model in a non-oil unloading state;

[0025] Figure 6 This is a schematic diagram of the oil unloading state of the exhaust mechanism provided by the embodiment of the utility model;

[0026] In the figure: 1, rocker arm body; 11, rocker arm shaft cavity; 12, first brake oil circuit; 13, second brake oil circuit; 14, unloading oil circuit; 2, one-way valve; 21, one-way spring; 22, steel ball; 3, actuator; 31, brake screw; 32, brake spring; 33, brake piston; 34, spring seat; 4, exhaust mechanism; 41, elephant foot; 42, first spring; 43, spring sleeve; 44, movable pin; 441, third unloading oil circuit; 45, second spring; 46, adjustment screw; 461, first unloading oil circuit; 462, second unloading oil circuit;

[0027] In order to show the positions of various parts, the distances or sizes between them are exaggerated and the schematic diagram is for reference only. DETAILED DESCRIPTION

[0028] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0029] Compression-release braking: When the engine is in a long downhill process and the compression stroke is about to end, the exhaust valve bridge opens to release compressed air to reduce work. This structure is called a compression-release braking structure.

[0030] As mentioned in the background technology, the prior art (publication number CN114033525A) discloses a brake rocker arm, a brake rocker arm system and a vehicle, wherein after the engine brake is turned on, the first action end of the piston moves and stably stays in the second position under the action of the hydraulic oil, and as the piston contacts the exhaust valve bridge and presses down the exhaust valve bridge, the reset push rod also moves continuously until the second end of the reset push rod touches the base close to the position of the exhaust valve bridge. At this time, the reset push rod moves relative to the rocker arm body in the direction close to the one-way valve under the action of the base, and after the first end acts on the one-way valve, the one-way valve opens the oil circuit, and the hydraulic oil in the piston chamber flows back to the oil circuit, causing the oil pressure acting on the piston to drop, and the first action end returns to the first position under the action of the elastic member, thereby achieving reset. The reset process of the brake rocker arm structure is to return the hydraulic oil of the one-way valve, so it is necessary to add a base at the corresponding position of the one-way valve of the brake rocker arm, and the structure is complicated.

[0031] like Figure 1 As shown, in one embodiment of the utility model, a compression-release brake rocker arm assembly is proposed, and the brake rocker arm assembly includes a rocker arm body 1, a one-way valve 2, an actuator 3 and an exhaust mechanism 4. A rocker arm shaft cavity 11 is provided on the rocker arm body 1, and the one-way valve 2, the actuator 3 and the exhaust mechanism 4 are arranged on the rocker arm body 1 in sequence, and the distances from the one-way valve 2, the actuator 3 and the exhaust mechanism 4 to the rocker arm shaft cavity 11 increase in sequence, that is, the distance from the exhaust mechanism 4 to the rocker arm shaft cavity 11 is greater than the distance from the actuator 3 to the rocker arm shaft cavity 11, and the distance from the actuator 3 to the rocker arm shaft cavity 11 is greater than the distance from the one-way valve 2 to the rocker arm shaft cavity 11, and the two closest ones of the one-way valve 2, the actuator 3 and the exhaust mechanism 4 are connected by an oil circuit, that is, the one-way valve 2 is connected to the actuator 3 through the oil circuit, and the actuator structure is connected to the exhaust mechanism 4 through the oil circuit.

[0032] like Figure 5As shown, the exhaust mechanism 4 includes an adjusting screw 46, a movable pin 44 and an elephant foot 41. The adjusting screw 46 has a central hole. A first oil discharge passage 461 is provided on the side wall of the adjusting screw 46. The first oil discharge passage 461 is arranged along the radial direction of the adjusting screw 46. A second oil discharge passage 462 is provided at the upper end of the adjusting screw 46. The movable pin 44 is inserted into the central hole of the adjusting screw 46 and can move up and down in the adjusting screw 46. The upper end of the adjusting screw 46 has a blind hole. The upper end of the blind hole is connected to the second oil discharge passage 462 of the adjusting screw 46. A third oil discharge passage 441 is provided on the side wall of the movable pin 44. The third oil discharge passage 441 is arranged along the radial direction of the movable pin 44 and is connected to the blind hole in the movable pin 44. The elephant foot 41 can push the movable pin 44 to move relative to the adjusting screw 46, so that the first oil discharge passage 461, the second oil discharge passage 462 and the third oil discharge passage 441 are connected to realize oil discharge. Among them, the words "upper" and "lower" appearing in the utility model only indicate that they are consistent with the upper and lower directions of the drawings themselves, and do not limit the structure. They are only for the convenience of describing the utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the utility model.

[0033] In the brake rocker arm assembly of the utility model, a movable pin 44 and an oil unloading path are added in the exhaust mechanism 4. When the elephant foot 41 rises under the reaction of the valve bridge, the movable pin 44 is compressed to move relative to the adjustment screw 46, so that the first oil unloading path 461 on the adjustment screw 46, the third oil unloading path 441 on the movable pin 44 and the second oil unloading path 462 on the adjustment screw 46 form a conductive oil unloading path for oil unloading. That is, the brake oil is unloaded through the execution structure instead of flowing back through the one-way valve 2, and the oil unloading process is realized by the rocker arm assembly cooperating with the existing structure (valve bridge, elephant foot 41), without adding a matching structure such as a base, and the structure is simple.

[0034] The rocker arm shaft chamber 11 is connected to the one-way valve 2 through the first brake oil circuit 12, and the one-way valve 2 is connected to the actuator 3 through the second brake oil circuit 13. The one-way valve 2 realizes one-way communication from the first brake oil circuit 12 to the second brake oil circuit 13. Specifically, Figure 3 As shown, the one-way valve 2 includes a screw plug, a one-way spring 21 and a steel ball 22, and has a conical hole on the rocker arm body 1. The lower end of the conical hole is connected to the first brake oil circuit 12, and the upper end is connected to the oil chamber in the one-way valve 2. The oil chamber in the one-way valve 2 is connected to the second brake oil circuit 13. The steel ball 22 abuts against the upper end of the conical hole toward the oil chamber, the lower end of the one-way spring 21 abuts against the steel ball 22, and the upper end abuts against the screw plug.

[0035] When the engine is in a braking state, under the control of the external solenoid valve, the first brake oil circuit 12 is opened, and the brake lubricating oil flows from the rocker arm shaft cavity 11 through the first brake oil circuit 12 into the one-way valve 2. Figure 2 , Figure 3 When the brake lubricating oil enters the one-way valve 2, the brake lubricating oil pressure overcomes the elastic force of the one-way spring 21, opens the one-way valve 2, and the brake lubricating oil enters the interior of the actuator 3 through the second brake oil circuit 13.

[0036] The actuator 3 is connected to the exhaust mechanism 4 through the unloading oil circuit 14. The actuator 3 has a brake chamber, and the second brake oil circuit 13 and the unloading oil circuit 14 are both connected to the brake chamber. Figure 4 As shown, the actuator 3 includes a brake screw 31, a brake spring 32, a brake piston 33 and a spring seat 34; the spring seat 34 is sleeved on the brake screw 31, the brake piston 33 is a cylindrical shape with a closed lower end, the brake piston 33 is sleeved on the lower end of the brake screw 31, and the upper end of the brake piston 33 is clamped with the spring seat 34. Specifically, the brake piston 33 and the spring seat 34 can be clamped by a clamp. The upper end of the brake spring 32 abuts on the spring seat 34, the lower end of the brake screw 31 has a retaining ring, and the lower end of the spring abuts on the retaining ring of the brake screw 31.

[0037] The brake spring 32 has a tendency to move the brake piston 33 upward, that is, in the initial state, the brake piston 33 retracts into the brake chamber. When the one-way valve 2 takes in oil through the second brake oil circuit 13 and the exhaust mechanism 4 does not unload oil, the brake oil pushes the brake piston 33 downward, thereby opening the brake piston 33.

[0038] like Figure 5 , Figure 6 As shown, the elephant foot 41 is slidably mounted on the rocker arm body 1, the lower end of the elephant foot 41 is used to press the valve bridge, the upper end of the elephant foot 41 has a blind hole, and a first spring 42 is installed in the blind hole, the lower end of the first spring 42 abuts on the elephant foot 41, and the upper end abuts on the adjusting screw 46. The first spring 42 has a tendency to move the elephant foot 41 downward, that is, in the initial state, the elephant foot 41 is located at the lower side. The elephant foot 41 can be replaced by other parts, and the upper limit of the elephant foot 41 can be controlled by the adjusting screw 46.

[0039] Furthermore, the exhaust mechanism 4 also includes a spring sleeve 43, which is installed at the lower end of the adjusting screw 46, and the movable pin 44 is inserted into the spring sleeve 43. A second spring 45 is arranged between the adjusting screw 46 and the movable pin 44, and the second spring 45 has a tendency to make one end of the movable pin 44 protrude out of the spring sleeve 43.

[0040] When the exhaust enters the main lift, the elephant foot 41 moves up, and the movable pin 44 is compressed by the elephant foot 41. At this time, the lubricating oil is discharged from the adjustment screw 46 through the unloading oil path 14, the first unloading oil path 461, the third unloading oil path 441, and the second unloading oil path 462 in sequence (such as Figure 6 As shown), the main lift valve bridge lift remains unchanged.

[0041] The working principle of the above rocker arm assembly:

[0042] When the engine is in a braking state, under the control of the external solenoid valve, the first brake oil circuit 12 is opened, and the brake lubricating oil flows from the rocker arm shaft cavity 11 through the first brake oil circuit 12 into the one-way valve 2. Figure 2 , Figure 3 When the brake lubricating oil enters the one-way valve 2, the brake lubricating oil pressure overcomes the elastic force of the one-way spring 21, opens the one-way valve 2, and the brake lubricating oil enters the interior of the actuator 3 through the second brake oil circuit 13.

[0043] Before the lubricating oil enters the brake mechanism, the brake piston 33 is in a closed state (i.e., the brake piston 33 retracts upward) under the action of the brake spring 32 and the brake screw 31. When the lubricating oil enters the brake oil chamber from the second brake oil circuit 13, the pressure in the brake oil chamber overcomes the elastic force of the brake spring 32 and opens the brake piston 33 (i.e., the brake piston 33 bulges downward).

[0044] The lubricating oil entering the unloading oil passage 14 enters the first unloading oil passage 461. Near the compression top dead center, the valve bridge clearance is 3 mm. The movable pin 44 is located at the lower side under the action of the second spring 45. The first unloading oil passage 461 is blocked by the movable pin 44 (such as Figure 5 As shown), at this time, the brake oil chamber pressure is maintained, and near the compression top dead center, compression release braking is achieved by relying on camshaft drive.

[0045] When the exhaust enters the main lift, the elephant foot 41 moves up, and the movable pin 44 is compressed by the elephant foot 41. At this time, the lubricating oil is discharged from the adjustment screw 46 through the unloading oil path 14, the first unloading oil path 461, the third unloading oil path 441, and the second unloading oil path 462 in sequence (such as Figure 6 As shown), the main lift valve bridge lift remains unchanged.

[0046] When the engine is in a non-braking state, the lubricating oil pressure in the first brake oil circuit 12 drops. At this time, the steel ball of the one-way valve 2 blocks the brake oil circuit under the action of the one-way valve 2 spring to prevent the lubricating oil from entering the actuator 3 to open the brake piston 33.

[0047] At this time, the excess oil in the actuator 3, under the action of the brake spring 32, releases the lubricating oil from the adjustment screw 46 through the unloading oil path 14, the first unloading oil path 461, the third unloading oil path 441, and the second unloading oil path 462, thereby realizing a non-braking state without oil pressure. At this time, the lubrication at the adjustment screw 46 is performed through the splash oil hole to ensure the reliability of the adjustment screw 46.

[0048] Based on the above-mentioned compression-release brake rocker arm assembly, an embodiment of the utility model further provides an engine, in which the compression-release brake rocker arm assembly described in the above-mentioned embodiment is arranged. Since the above-mentioned compression-release brake rocker arm assembly has the above-mentioned technical effect, the technical effect of the engine using the compression-release brake rocker arm assembly please refer to the above-mentioned embodiment.

[0049] Although the above describes the specific implementation methods of the utility model in combination with the accompanying drawings, it is not intended to limit the scope of protection of the utility model. Technical personnel in the relevant field should understand that on the basis of the technical solution of the utility model, various modifications or deformations that can be made by technical personnel in this field without creative work are still within the scope of protection of the utility model.

Claims

1. A compression release brake rocker arm assembly, characterized in that: include: A rocker arm body, an actuator and an exhaust mechanism, wherein the actuator and the exhaust mechanism are arranged on the rocker arm body and are connected through an oil passage; The exhaust mechanism includes an adjusting screw, a movable pin and an elephant foot. The movable pin is inserted into the adjusting screw. A first oil unloading passage is arranged on the side wall of the adjusting screw, and a second oil unloading passage is arranged at the end. A third oil unloading passage is arranged on the side wall of the movable pin. The elephant foot can push the movable pin to move relative to the adjusting screw, so that the first oil unloading passage, the second oil unloading passage and the third oil unloading passage are connected.

2. The compression release brake rocker arm assembly according to claim 1, characterized in that: It also includes a one-way valve, a rocker arm shaft cavity is provided on the rocker arm body, the one-way valve, the actuator and the exhaust mechanism are arranged on the rocker arm body in sequence, the distances from the one-way valve, the actuator and the exhaust mechanism to the rocker arm shaft cavity increase in sequence, and the two closest ones of the one-way valve, the actuator and the exhaust mechanism are connected through an oil circuit.

3. The compression release brake rocker arm assembly according to claim 2, characterized in that: The rocker arm shaft cavity is communicated with the one-way valve through the first brake oil circuit, and the one-way valve is communicated with the actuator through the second brake oil circuit. The one-way valve realizes one-way conduction from the first brake oil circuit to the second brake oil circuit.

4. The compression release brake rocker arm assembly according to claim 3, characterized in that: The one-way valve includes a screw plug, a one-way spring and a steel ball, and has a conical hole on the rocker arm body. One end of the conical hole is connected to the first brake oil circuit, and the other end is connected to the oil chamber in the one-way valve. The oil chamber in the one-way valve is connected to the second brake oil circuit. The steel ball rests on one end of the conical hole facing the oil chamber, one end of the one-way spring rests on the steel ball, and the other end rests on the screw plug.

5. The compression release brake rocker arm assembly according to claim 3, characterized in that: The actuator is communicated with the exhaust mechanism through an unloading oil circuit. A brake chamber is provided in the actuator. Both the second brake oil circuit and the unloading oil circuit are communicated with the brake chamber.

6. The compression release brake rocker arm assembly according to claim 5, characterized in that: The actuator includes a brake screw, a brake spring, a brake piston and a spring seat; the spring seat is sleeved on the brake screw, the brake piston is sleeved on the end of the brake screw, and one end of the brake piston is clamped with the spring seat, one end of the brake spring is against the spring seat, and the other end is against the brake screw.

7. The compression release brake rocker arm assembly according to claim 6, characterized in that: The brake piston and the spring seat are clamped together by a clamp.

8. The compression release brake rocker arm assembly according to claim 1, characterized in that: The elephant foot is slidably installed on the rocker arm body, one end of the elephant foot is used for crimping the valve bridge, the other end of the elephant foot has a blind hole, a first spring is installed in the blind hole, one end of the first spring abuts on the elephant foot, and the other end abuts on the adjusting screw.

9. The compression release brake rocker arm assembly according to claim 8, characterized in that: The exhaust mechanism also includes a spring sleeve, which is installed at the end of the adjusting screw. The movable pin is inserted into the spring sleeve. A second spring is arranged between the adjusting screw and the movable pin. The second spring has a tendency to make one end of the movable pin protrude out of the spring sleeve.

10. An engine, characterized in that: Comprising a compression-release brake rocker arm assembly as described in any one of claims 1-9.

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