Valve bridge with failure protection and engine
By setting guide grooves and guide pins on the side of the plunger of the valve bridge, combined with the internal and external double return spring design, the problem of the locking pin cannot be reset after unlocking the collapse mechanism is solved, ensuring that the engine can still be normal when the locking pin cannot be locked. Operation, the failure protection of the valve bridge is achieved.
Patent Information
- Application Number
- CN202420849275.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-22
- Publication Date
- 2024-12-20
- Estimated Expiration
- 2034-04-22
AI Technical Summary
The valve bridge collapse mechanism in existing engines cannot be reset normally after the locking pin is unlocked, resulting in the engine being unable to start normally after braking, and there are various failure risks.
A valve bridge with failure protection is designed. By setting the guide groove and guide pin on the side of the plunger, the rotation of the plunger is restricted, and the guide hole and locking pin hole are provided on the valve bridge body, and the internal and external double return is adopted. The bit spring design ensures automatic guidance and adaptive locking of the lock pin in the plunger to reduce locking pin wear.
Effectively prevent the valve bridge from failing due to the rotation of the plunger, ensure the normal start and operation of the engine, ensure that the valve can still be opened when the locking pin cannot be locked, realize the continuous operation of the engine, and reduce the plunger reset speed and locking. Pins wear.
Smart Images
Figure CN222208039U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of engines, in particular to a valve bridge with failure protection and an engine. Background Art
[0002] The in-cylinder braking process of the engine is to transfer the engine pressure lubricating oil to the brake actuator through the solenoid valve, and utilize the on and off of the pressure lubricating oil to realize the activation and exit of the brake actuator, thereby realizing the control of the valve action by the brake actuator. Combined with the special valve lift design, the exhaust valve can be opened near the top dead center to realize compression release braking.
[0003] Many existing engines use valve bridges as brake actuators, and the valve bridge is driven downward by the rocker arm to open the lower valve. In high-power engine braking, a crush mechanism is designed inside the valve bridge. The on and off of the pressure lubricating oil controls the locking and unlocking of the crush mechanism. When the crush mechanism is unlocked, the exhaust rocker arm directly drives the plunger of the crush mechanism to move while the valve bridge does not move. This can eliminate the normal exhaust process, and combined with the specially designed brake cam profile, two compression release brakes can be achieved within four strokes. However, the existence of the crush mechanism also makes the engine have multiple failure risks. For example, if the plunger rotates or the lock pin gets stuck during the action, the crush mechanism cannot be restored from the unlocked state to the locked state, resulting in the engine being unable to start normally after braking. Utility Model Content
[0004] In view of the deficiencies in the above-mentioned prior art, the utility model provides a valve bridge and an engine with failure protection, which can prevent the plunger from rotating after the locking pin is unlocked, resulting in the locking pin being unable to reset normally, and has a failure protection mechanism, so that the valve can still be opened to allow the engine to run when the locking pin cannot be locked.
[0005] In order to achieve the above objectives, the present invention adopts one or more of the following technical solutions:
[0006] In a first aspect, a valve bridge with failure protection is provided, comprising:
[0007] A valve bridge body, wherein a collapse mechanism is arranged in the valve bridge body, wherein the collapse mechanism comprises a plunger, wherein a cavity for the passage of pressure oil is longitudinally arranged in the plunger, and a guide groove is radially opened on the side surface of the plunger, wherein the guide groove cooperates with a guide pin radially passing through the guide groove to limit the rotation of the plunger; and the guide groove has a set length along the axial direction of the plunger.
[0008] Preferably, the length of the guide groove is smaller than the valve lift, so that the valve can still be opened after the valve bridge lock fails.
[0009] Preferably, a guide hole coaxial with the guide groove is formed on the valve bridge body, and a guide pin passes through the guide hole and extends into the guide groove to limit the rotation of the plunger.
[0010] Preferably, the guide hole is arranged obliquely relative to the length direction of the valve bridge body.
[0011] Preferably, a plunger return spring is arranged at the bottom of the plunger, and the plunger return spring comprises an inner ring spring and an outer ring spring which are arranged coaxially with the plunger.
[0012] Preferably, a lock pin hole perpendicular to the plunger axis is provided on the valve bridge body, and a lock pin is provided in the lock pin hole; a lock pin return spring is connected to the side of the lock pin away from the plunger.
[0013] Preferably, the locking pin hole is a blind hole; and the locking pin hole is arranged obliquely relative to the length direction of the valve bridge body.
[0014] Preferably, a locking hole opposite to the locking pin hole is opened on the side of the plunger, the cross-section of the locking hole is pear-shaped with a small top and a large bottom and a smooth transition, and the longitudinal length of the locking hole is greater than the longitudinal length of the locking pin hole.
[0015] Preferably, an actuator pin is installed at one end of the valve bridge body in the length direction, and the actuator pin is clearance-matched with the valve bridge body.
[0016] In a second aspect, an engine is provided, comprising a valve bridge with failure protection as described above.
[0017] By adopting the above technical solution, the beneficial effects of the utility model are as follows:
[0018] 1. The utility model is provided with a plunger with a guide groove, which cooperates with a guide pin to prevent the valve bridge from failing due to the rotation of the plunger, thereby ensuring the normal starting and operation of the engine.
[0019] 2. The guide length of the guide groove of the utility model is set to be smaller than the valve lift, so that the valve can still be opened and the engine can run even if the valve bridge fails to lock due to other reasons.
[0020] 3. The utility model is provided with a plunger with a pear-shaped lock pin hole, so as to realize automatic guiding and adaptive locking of the lock pin in the plunger, and the pear-shaped transition can reduce the wear of the lock pin.
[0021] 4. The bottom of the collapse structure of the utility model adopts an internal and external double return spring design to increase the plunger reset speed, so as to avoid the plunger flying off and plunger loss of control at high engine speed, and avoid the collision and impact between the plunger and the elephant foot. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] 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.
[0023] Figure 1 This is a schematic diagram of the structure of the first embodiment of the utility model;
[0024] Figure 2 This is an explosion diagram of the first embodiment of the utility model;
[0025] Figure 3 This is a schematic diagram of the valve bridge structure of the first embodiment of the utility model;
[0026] Figure 4 This is a schematic diagram of a plunger in Embodiment 1 of the present utility model;
[0027] Figure 5 It is a top view and a cross-sectional view of the first embodiment of the utility model;
[0028] Figure 6 This is a front view of the first embodiment of the utility model;
[0029] Figure 7 for Figure 6 A and C sectional views;
[0030] Figure 8 This is a schematic diagram of the lock pin unlocking process of the first embodiment of the utility model;
[0031] Fig. 9 This is a schematic diagram of failure protection of the first embodiment of the utility model.
[0032] In the figure: 1, valve bridge body; 11, guide hole; 12, lock pin hole; 13, actuator pin;
[0033] 2. Collapse mechanism; 21. Plunger; 211. Oil chamber; 212. Guide groove; 213. Guide pin; 214. Locking hole; 215. Locking pin; 216. Locking pin return spring; 217. Screw plug; 221. Inner ring spring;
[0034] 222, outer ring spring;
[0035] 3. Elephant foot; 4. Other internal structures of the engine. DETAILED DESCRIPTION
[0036] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the utility model. Unless otherwise specified, all technical and scientific terms used in the utility model have the same meanings as those commonly understood by ordinary technicians in the technical field to which the utility model belongs. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.
[0037] Embodiment 1
[0038] In a typical embodiment of the present application, a valve bridge with failure protection is provided, such as Figure 1-9 As shown, it includes a valve bridge body 1, in which a collapse mechanism 2 is arranged, and the collapse mechanism 2 includes a plunger 21. An oil chamber 211 is longitudinally arranged in the plunger, and the oil chamber is a cavity for pressure oil to pass through. A guide groove 212 is radially opened on the side of the plunger, and the guide groove cooperates with a guide pin 213 radially passing through the guide groove to limit the rotation of the plunger, so as to prevent the locking pin from being unable to be reset normally due to the rotation of the plunger after the locking pin is unlocked, thereby enhancing reliability.
[0039] A guide hole 11 coaxial with the guide groove is provided on the valve bridge body 1, and a guide pin 213 passes through the guide hole 11 and extends into the guide groove 212 to limit the rotation of the plunger 21. As shown in the figure, the guide groove 212 and the guide hole 11 are arranged on both sides of the plunger 21, and two guide pins 213 extend inward from the outside of the valve bridge body respectively to prevent the locking hole and the locking pin from being misaligned due to the rotation of the plunger, resulting in the locking pin being unable to be reset normally, causing the valve bridge to fail, and the engine being unable to start after braking, thereby ensuring the normal operation of the engine and realizing failure protection. The guide hole is arranged obliquely relative to the length direction of the valve bridge body, which can make full use of the space and reduce the risk of interference between the valve bridge and other structures of the engine.
[0040] It is easy to understand that the guide pin extends into the guide groove through the valve bridge body to limit the rotation of the plunger and will not extend into the oil chamber. At the same time, in order to ensure that the guide pin does not affect the axial movement of the plunger, the guide groove has a set length along the axial direction of the plunger, and the guide groove and the guide pin can slide up and down relative to each other.
[0041] A lock pin hole 12 perpendicular to the plunger axis is provided on the valve bridge body 1, and a lock pin 215 is coaxially provided in the lock pin hole; a lock pin return spring 216 is connected to the side of the lock pin away from the plunger, and the valve bridge is switched between the locked and unlocked states through the action of the lock pin.
[0042] The collapse mechanism 2 further comprises a plunger return spring, which is arranged at the bottom of the plunger 21 and is compressed when the plunger descends.
[0043] like Figure 8 As shown, when the engine brakes, the pressure oil enters the valve bridge body 1 through the oil chamber 211 in the plunger, pushing the lock pin 215 to move away from the plunger, compressing the lock pin reset spring 216. After the lock pin is retracted into the valve bridge body, the valve bridge body and the plunger are unlocked. At this time, the exhaust rocker arm is pressed down, and the plunger 21 is pushed down by the elephant foot 3, but the valve bridge body does not move. When the oil filling stops, the exhaust rocker arm stops pressing down and returns upward. Under the action of the lock pin reset spring 216, the lock pin 215 returns from the valve bridge body to the plunger, and reconnects the plunger and the valve bridge body. At this time, the exhaust rocker arm is pressed down, and the plunger drives the valve bridge body to move downward, opening the valve located below the valve bridge.
[0044] After the lock pin is unlocked, the plunger moves downward under the action of the elephant foot, and the valve bridge body does not move at this time. When the elephant foot stops pressing down and moves upward in the return stroke, the plunger moves upward and resets under the action of the plunger return spring.
[0045] When the exhaust rocker arm's elephant foot returns from downward movement, the plunger returns to its original position under the action of the plunger return spring. If the plunger return speed is slower than the upward return speed of the elephant foot, the plunger will temporarily detach from the elephant foot and collide with the elephant foot during the return, causing noise and easily damaging components. To increase the plunger return speed, Figure 2 , 5 As shown, the plunger return spring adopts an inner and outer double return spring design, including a coaxially arranged inner ring spring 221 and an outer ring spring 222, which can ensure that the plunger does not fly off when the engine is running at high speed (such as above 2300r / min) and avoid plunger loss of control.
[0046] A locking hole 214 is provided on the side of the plunger 21, which is opposite to the locking pin hole. In the locked state, the locking pin 215 is inserted into the locking hole 214, and the plunger 21 is connected to the valve bridge body 1. After the locking pin is unlocked, the plunger leaves the locking hole and retracts into the valve bridge body under the action of the pressure oil; then, the plunger is reinserted into the locking hole and locked under the action of the locking pin return spring.
[0047] After the lock pin is unlocked, the plunger may not be able to re-enter the locking hole to lock it due to reasons such as the lock pin being stuck. In this case, the valve bridge body does not move when the foot presses down on the plunger, causing the valve to fail to open, resulting in valve bridge failure and the engine failing to start. Therefore, the longitudinal length of the lock pin guide groove is designed to be shorter than the valve lift, which is the distance the valve bridge body needs to move downward to fully open the valve. At this time, if Fig. 9 As shown, after the guide pin contacts the plunger, the elephant foot is still moving downward, so the elephant foot will drive the entire valve bridge to move together, and can also open the valve to a certain extent. This can ensure that after the valve bridge fails due to the inability to lock the locking pin, the valve can still be opened and the engine can still enter the operating state, thereby realizing the failure protection of the valve bridge from another angle.
[0048] In addition, in this embodiment, Figure 4 As shown, the cross section of the locking hole 214 is pear-shaped with a small top and a large bottom and a smooth transition, the longitudinal length of the locking hole 215 is greater than the longitudinal length of the locking pin hole 12, and the lower diameter of the pear-shaped locking hole is greater than the diameter of the locking pin hole. In the locked state, the plunger can move upward under the action of the plunger return spring, and the valve clearance set in consideration of the thermal expansion of the valve is adaptively adjusted, that is, the plunger moves upward a portion more under the action of the elastic force to enter the clearance, at which time the locking pin 215 will enter the lower half of the larger diameter of the pear-shaped locking hole 214, and the locking pin 215 is temporarily out of contact with the plunger 21, to avoid excessive wear of the locking pin when adjusting the valve clearance.
[0049] like Figure 1-2 As shown, an actuator pin 13 is installed at one end of the valve bridge body 1 in the length direction. The actuator pin is assembled with the valve bridge body. The assembly method is that the actuator pin and the assembly hole opened in the valve bridge body are matched with each other in a clearance. The actuator pin can move axially under the action of the brake rocker arm to realize the braking function. A brake valve is arranged below the actuator pin. The upper part of the actuator pin contacts the brake rocker arm. When the engine brakes, the brake rocker arm rotates to press the actuator pin downward to open the brake valve below.
[0050] To avoid the injector and other structures inside the engine, such as Figure 3 As shown, the lock pin hole 12 on the valve bridge body is designed as a blind hole, and is arranged obliquely relative to the length direction of the bridge body. The blind hole is processed on one side, which effectively shortens the length of the lock pin hole on the valve bridge body. The obliquely arranged lock pin hole can fully utilize the space of the valve bridge body while avoiding the internal structure of the engine, and can enhance the structural strength of the valve bridge body itself. Specifically, lock pins are distributed on both sides of the plunger, and the lock pin on one side is connected to the inner wall of the blind hole through a lock pin reset spring, and the lock pin on the other side is connected to the lock pin reset spring and a screw plug in sequence along the lock pin hole, and is fixed by the screw plug.
[0051] Embodiment 2
[0052] This embodiment provides an engine, including a valve bridge with failure protection of the first embodiment, which can avoid the failure of the valve to open and the engine to start due to the inability of the plunger to return to the unlocked state, thereby ensuring the operation of the engine.
[0053] The above description is only a preferred embodiment of the utility model and is not intended to limit the utility model. For those skilled in the art, the utility model may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.
Claims
1. A valve bridge with failure protection, characterized in that: include A valve bridge body, wherein a collapse mechanism is arranged in the valve bridge body, wherein the collapse mechanism comprises a plunger, wherein a cavity for the passage of pressure oil is longitudinally arranged in the plunger, and a guide groove is radially opened on the side surface of the plunger, wherein the guide groove cooperates with a guide pin radially passing through the guide groove to limit the rotation of the plunger; and the guide groove has a set length along the axial direction of the plunger.
2. A valve bridge with failure protection as claimed in claim 1, characterized in that: The length of the guide groove is smaller than the valve lift.
3. A valve bridge with failure protection as claimed in claim 1, characterized in that: A guide hole coaxial with the guide groove is provided on the valve bridge body, and a guide pin passes through the guide hole and extends into the guide groove to limit the rotation of the plunger.
4. A valve bridge with failure protection as claimed in claim 3, characterized in that: The guide hole is arranged obliquely relative to the length direction of the valve bridge body.
5. A valve bridge with failure protection as claimed in claim 1, characterized in that: A plunger return spring is arranged at the bottom of the plunger, and the plunger return spring comprises an inner ring spring and an outer ring spring which are arranged coaxially with the plunger.
6. A valve bridge with failure protection as claimed in claim 1, characterized in that: A lock pin hole perpendicular to the plunger axis is arranged on the valve bridge body, and a lock pin is arranged in the lock pin hole; a lock pin return spring is connected to the side of the lock pin away from the plunger.
7. A valve bridge with fail-safe protection as claimed in claim 6, characterized in that: The locking pin hole is a blind hole; the locking pin hole is arranged obliquely relative to the length direction of the valve bridge body.
8. A valve bridge with fail-safe protection as claimed in claim 6, characterized in that: A locking hole opposite to the locking pin hole is formed on the side of the plunger, the cross section of the locking hole has a smooth transition, and the longitudinal length of the locking hole is greater than the longitudinal length of the locking pin hole.
9. A valve bridge with failure protection as claimed in claim 1, characterized in that: An actuating pin is installed at one end of the valve bridge body in the length direction, and the actuating pin is clearance-matched with the valve bridge body.
10. An engine, characterized in that: It comprises a valve bridge with failure protection as described in any one of claims 1 to 9.