Radially stable support roller tappet

Abstract

The application relates to a radial stabilizing support roller tappet which comprises a shell, the inner wall of the shell is fixed with a bridging seat, the inner wall of the shell is embeddedly installed with a pin shaft, the surface of the pin shaft is connected with a cam roller eccentrically arranged with the pin shaft, the inside of the bridging seat is slidably connected with an adapter rod, the top of the bridging seat is installed with a radial shield which is sleeved on the outside of the adapter rod, the bottom of the radial shield extends to the inside of the bridging seat, the inside of the radial shield is provided with an air groove, the inside of the air groove is slidably connected with a movable shield, the inside surface of the movable shield is installed with a connecting rod, the tail end of the connecting rod is fixedly connected with the surface of the adapter rod, the connecting relationship among the movable shield, the connecting rod and the adapter rod is utilized, so that the movable shield is synchronously lifted when the adapter rod is in a lifting state, and the effective radial support of the adapter rod in the lifting state is increased, so that the roller tappet is ensured to have stable radial support.

Description

TECHNICAL FIELD

[0001] The radial stabilizing support roller tappet relates to the field of roller tappets, in particular to a radial stabilizing support roller tappet. BACKGROUND

[0002] The tappet is the main component of the valve train, which uses oil pressure to transmit the force on the camshaft eccentric to the valve, and the roller tappet is widely used as a kind of tappet, but the complexity of the structure needs to be paid attention to in the use process to reduce the weight of the roller tappet.

[0003] To solve the problem of complex structure, some roller tappets in the market use lightweight design with simplified structure, which has a certain market share.

[0004] The Chinese invention patent CN202110243547.4 specification discloses a roller tappet for a high-pressure fuel pump, which has a housing, a cam roller is arranged in the annular end face of the drive side of the housing, a bridge protrudes from the inner surface of the housing at the rear side of the cam roller, a pin for contacting the pump piston extends from the outer side of the bridge away from the cam roller, the bridge is connected with the housing in one piece, and the pin is a separate adapter for the pump piston that protrudes beyond the annular end face of the driven side of the housing, the outer end face of the adapter forms a direct abutting portion for the pump piston, wherein the contact area between the inner end face of the adapter and the outer side of the bridge serves as a hinge mechanism, a ring is integrally extended from the outer side of the bridge, the ring surrounds the ring of the adapter on the inner end face of the adapter with a gap, and the ring is integrally extended from the outer side of the bridge to limit the inclination of the adapter relative to the housing.

[0005] The roller tappet described above uses a simplified structure to achieve lightweight of the tappet in design, but the effective contact area with the bridge is constant when the adapter moves up and down, which causes the adapter to be effectively supported radially by the bridge when it rises, and is prone to radial displacement, affecting the effectiveness of the tappet. SUMMARY

[0006] In view of the above prior art, the technical problem to be solved by the present application is to increase the effective radial support area of the bridge and the adapter rod body by the movable radial shield when the adapter rises, so that the adapter in the lifting state can be stably and effectively supported radially during movement.

[0007] To solve the above problems, the application provides a radial stable support roller tappet, which comprises a shell, a bridging seat fixed to the inner wall of the shell, a pin shaft embedded in the inner wall of the shell, a cam roller arranged eccentrically on the surface of the pin shaft, an adapter rod slidingly connected to the inside of the bridging seat, a radial shield sleeved on the outside of the adapter rod and installed on the top of the bridging seat, and the bottom of the radial shield extending to the inside of the bridging seat, a gas groove arranged in the inside of the radial shield, a movable shield slidingly connected to the inside of the gas groove, a connecting rod installed on the inside surface of the movable shield, and the tail end of the connecting rod fixedly connected to the surface of the adapter rod.

[0008] In the radial stable support roller tappet, the connecting relationship among the movable shield, the connecting rod and the adapter rod is utilized to make the movable shield synchronously lifted when the adapter rod is in the lifting state, so that the effective radial support of the adapter rod in the lifting state is increased, thereby ensuring that the roller tappet has stable radial support.

[0009] As a further improvement of the application, the bottom of the movable shield is connected with a piston ring, the bottom wall of the gas groove is provided with an impact gas hole, the surface of the radial shield close to the bottom end is provided with an air inlet pipeline, one-way valves are arranged in the air inlet pipeline and the impact gas hole, the tail end of the air inlet pipeline extends to the surface of the bridging seat, and the impact gas hole extends to the bottom of the bridging seat.

[0010] As a further improvement of the application, the inside of the bridging seat is provided with a through hole, and the through hole is arranged in a staggered manner with the air inlet pipeline.

[0011] As a further improvement of the application, the surface of the movable shield is provided with a heat dissipation hole, and the movable shield is made of an alloy material.

[0012] As a further improvement of the application, the height of the movable shield is greater than the diameter of the cam roller, the height of the gas groove is greater than the height of the movable shield, and the air inlet pipeline is located below the piston ring.

[0013] As another improvement of the application, the inside of the movable shield is provided with an inwardly recessed support groove, one end of the connecting rod is connected with a rack arranged in the support groove, and the inner wall of the support groove is provided with a gear rod engaged with the rack.

[0014] As a further improvement of the application, the inner wall of the support groove is slidingly connected with a sealing baffle, the sealing baffle and the inner wall of the support groove form a pressure chamber, and the inside of the pressure chamber is filled with gas.

[0015] As a further improvement of the application, the gear rod and the inner wall of the support groove are connected through a bearing, the air pressure in the pressure chamber in the engaged state of the gear rod and the rack in the initial state is equal to the air pressure outside the shell, and the rack is connected with the sealing baffle.

[0016] To sum up, the beneficial effects of the present application are as follows:

[0017] In use of the present roller tappet, during the lifting of the adapter rod, the movable shield is lifted synchronously under the connecting action of the connecting rod, so that the effective radial support area of the adapter rod is increased, and the radial support of the adapter rod is strengthened, so that the adapter rod in the lifting state can obtain stable radial stable support, avoiding the radial deviation of the adapter rod during movement, affecting the accuracy of the work of the roller tappet;

[0018] With the lifting of the movable shield, the gas outside the bridge seat can enter the space below the piston ring in the gas groove through the gas inlet pipeline, and when the piston ring is lowered, the sucked gas can be discharged through the impact gas hole, so as to wash the surface of the rotating cam roller, avoiding the end deviation of the adapter rod and the subsequent possible radial deviation;

[0019] When the wall thickness of the bridge seat is reduced due to long-term sliding and lifting friction contact with the adapter rod, once the adapter rod deviates radially, the connecting rod will be pressed and approached to the inside of the support groove, at this time the sealing baffle slides inward, and under the influence of air pressure, the sealing baffle is difficult to continue to move, thereby preventing the adapter rod from continuing to deviate radially, so that the radial deviation distance of the adapter rod is controlled within a controllable tolerance range. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 The present application is a comparison diagram of the first embodiment and the prior art;

[0021] Figure 2 The present application is a schematic diagram of the overall structure of the first embodiment;

[0022] Figure 3 The present application is a schematic diagram of the internal structure of the first embodiment;

[0023] Figure 4 The present application is a schematic diagram of the bridge seat, movable shield and radial shield mounting structure of the first embodiment;

[0024] Figure 5 The present application is a comparison diagram of the lifting state of the adapter rod of the first embodiment;

[0025] Figure 6 The present application is a schematic diagram of the internal structure of the movable shield and the radial shield of the first embodiment;

[0026] Figure 7 The present application is a schematic diagram of the internal gas groove of the movable shield in the lifting state of the first embodiment;

[0027] Figure 8Fig. 1 is a schematic view of the internal cross-sectional structure of the bridge seat of the first embodiment of the present application;

[0028] Figure 9 Fig. 2 is a cross-sectional view of the second embodiment of the present application;

[0029] Figure 10 Fig. 3 is an enlarged schematic view of A of the second embodiment of the present application. Figure 9

[0030] Fig. 4 is a legend of the drawing;

[0031] 1, housing; 2, bridge seat; 21, through hole; 3, adapter rod; 4, radial shield; 41, movable shield; 42, air groove; 43, piston ring; 44, impact air hole; 45, air inlet pipe; 411, heat dissipation hole; 412, connecting rod; 5, pin shaft; 6, cam roller; 7, support groove; 71, pressure cavity; 72, sealing baffle; 73, gear rod; 74, rack. DETAILED DESCRIPTION

[0032] The two embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0033] First embodiment:

[0034] Figures 1-5 A radial stable support roller tappet is shown, which comprises a housing 1, the inner wall of the housing 1 is fixed with a bridge seat 2, the inner wall of the housing 1 is embeddedly installed with a pin shaft 5, the surface of the pin shaft 5 is connected with a cam roller 6 arranged eccentrically with the pin shaft 5, the inside of the bridge seat 2 is slidably connected with an adapter rod 3, the top of the bridge seat 2 is installed with a radial shield 4 which is sleeved around the outside of the adapter rod 3, and the bottom of the radial shield 4 extends to the inside of the bridge seat 2, the inside of the radial shield 4 is provided with an air groove 42, the inside of the air groove 42 is slidably connected with a movable shield 41, the inside surface of the movable shield 41 is installed with a connecting rod 412, and the tail end of the connecting rod 412 is fixedly connected with the surface of the adapter rod 3.

[0035] Specifically, when the roller tappet is used, the end of the pin shaft 5 is connected with a rotating part, which can drive the cam roller 6 to rotate, so that the eccentrically arranged cam roller 6 is in an eccentric state, at this time, the adapter rod 3 whose bottom surface is in contact with the surface of the cam roller 6 follows the rotation of the cam roller 6 to realize up and down movement, in the process of the upward movement of the adapter rod 3, the movable shield 41 is driven to rise synchronously under the connection action of the connecting rod 412, so that the effective radial support area of the adapter rod 3 is increased, and the radial support effect of the adapter rod 3 is strengthened, so that the adapter rod 3 in the rising state can obtain stable radial stable support effect, avoiding the radial deviation of the adapter rod 3 in the movement process, and affecting the accuracy of the roller tappet work.

[0036] Figures 6-8 ​The bottom of the movable shield 41 is connected with a piston ring 43, the bottom wall of the air groove 42 is provided with an impact air hole 44, the surface of the radial shield 4 near the bottom end is provided with an air inlet pipe 45, and the inside of the impact air hole 44 and the air inlet pipe 45 are both provided with a one-way valve, and the tail end of the air inlet pipe 45 extends to the surface of the bridge seat 2, and the impact air hole 44 extends to the bottom of the bridge seat 2.

[0037] Specifically, with the lifting of the movable shield 41, the piston ring 43 moves up and down synchronously in the air groove 42, and the gas outside the bridge seat 2 enters the space below the piston ring 43 in the air groove 42 through the air inlet pipe 45, and the suction gas is discharged through the impact air hole 44 when the piston ring 43 descends, the surface of the cam roller 6 in the rotating state is washed, the surface of the cam roller 6 is air-cooled and cleaned, the contact part of the bottom surface of the adapter rod 3 and the surface of the cam roller 6 is kept clean and unobstructed, and the end of the adapter rod 3 is prevented from deviating to cause the subsequent possible radial deviation.

[0038] The inside of the bridge seat 2 is provided with a through hole 21, and the through hole 21 is arranged in a staggered manner with the air inlet pipe 45.

[0039] Specifically, the through hole 21 is used for medium, and the medium includes but is not limited to air, lubricant and the like, and the staggered arrangement design prevents the through hole 21 from interfering with the air inlet pipe 45.

[0040] The surface of the movable shield 41 is provided with a heat dissipation hole 411, and the movable shield 41 is made of an alloy material.

[0041] Specifically, in the reciprocating motion of the adapter rod 3, the heat dissipation hole 411 on the surface of the movable shield 41 can be used for auxiliary heat dissipation, so that the adapter rod 3 and the movable shield 41 are prevented from being thermally deformed due to frequent lifting, and in addition, the movable shield 41 made of an alloy material has strong rigidity, thereby ensuring the radial support of the movable shield 41.

[0042] The height of the movable shield 41 is greater than the diameter of the cam roller 6, the height of the air groove 42 is greater than the height of the movable shield 41, and the air inlet pipe 45 is located below the piston ring 43.

[0043] Specifically, in order to ensure that the movable shield 41 effectively supports the adapter rod 3 in the radial direction, when the cam roller 6 moves to lift the adapter rod 3 to the highest point, the effective activity value and the effective maintenance support height value of the movable shield 41 can meet the radial support requirement in this state.

[0044] In addition, the installation position of the air inlet pipe 45 is designed such that when the piston ring 43 is in the lifting state and thus plays a pumping role on the space in the lower air groove 42, the air inlet pipe 45 can smoothly transport the gas outside the bridge seat 2 to the air groove 42, so as to be extruded and discharged when the piston ring 43 falls.

[0045] The second embodiment:

[0046] Figures 9-10 The same or corresponding parts as in the first embodiment are denoted by the same reference numerals, and only the differences from the first embodiment will be described below for the sake of brevity. The second embodiment differs from the first embodiment in that the inner part of the movable shield 41 is provided with an inner support groove 7, one end of the connecting rod 412 is connected to a rack 74 inside the support groove 7, and the inner wall of the support groove 7 is provided with a gear rod 73 engaged with the rack 74.

[0047] The inner wall of the support groove 7 is slidingly connected to a sealing baffle 72, the sealing baffle 72 and the inner wall of the support groove 7 form a pressure chamber 71, and the inside of the pressure chamber 71 is filled with gas.

[0048] The gear rod 73 is connected to the inner wall of the support groove 7 by a bearing, and in the initial state, the gas pressure in the pressure chamber 71 is equal to the external gas pressure of the shell 1 when the gear rod 73 is engaged with the rack 74, and the rack 74 is connected to the sealing baffle 72.

[0049] Specifically, when the wall thickness of the bridge seat 2 is not reduced due to wear of the inner wall, the connecting rod 412 is in a constant support state under the engagement and locking action of the gear rod 73 and the rack 74, and when the wall thickness of the bridge seat 2 is reduced due to long-term sliding and lifting friction contact with the adapter rod 3, the adapter rod 3 will cause the connecting rod 412 to be extruded and close to the inside of the support groove 7 as soon as it occurs radial deviation, at which time the sealing baffle 72 slides inward, and under the influence of the gas pressure, the sealing baffle 72 is difficult to continue to move, thereby preventing the adapter rod 3 from continuing to deviate radially, so that the radial deviation distance of the adapter rod 3 is controlled within a controllable tolerance range.

[0050] Before the movement of the sealing baffle 72 described above, the pressure in the pressure chamber 71 is equal to the external gas pressure of the shell 1 in the initial state, and after the movement of the sealing baffle 72, the pressure in the pressure chamber 71 is increased, so that the resistance to the continued radial deviation of the adapter rod 3 is increased, thereby preventing the increase of the radial deviation.

[0051] The above embodiments adopted by the present application are not limited to the scope of the present application, and various changes made within the knowledge of those skilled in the art without departing from the concept of the present application still fall within the protection scope of the present application.

Claims

1. A radially stable support roller tappet comprising a housing (1), characterized in that: The inner wall of the shell (1) is fixed with a bridging seat (2), the inner wall of the shell (1) is inlaid with a pin shaft (5), the surface of the pin shaft (5) is connected with a cam roller (6) arranged eccentrically with the pin shaft (5), the inside of the bridging seat (2) is slidably connected with an adapter rod (3), characterized in that: the top of the bridging seat (2) is provided with a radial shield (4) sleeved on the outside of the adapter rod (3), and the bottom of the radial shield (4) extends into the inside of the bridging seat (2), the inside of the radial shield (4) is provided with an air groove (42), the inside of the air groove (42) is slidably connected with a movable shield (41), the inside surface of the movable shield (41) is provided with a connecting rod (412), and the tail end of the connecting rod (412) is fixedly connected with the surface of the adapter rod (3). The bottom of the movable shield (41) is connected with a piston ring (43), the bottom wall of the air groove (42) is provided with an impact air hole (44), the surface of the radial shield (4) is provided with an air inlet pipe (45) near the bottom end, and the inside of the air inlet pipe (45) and the impact air hole (44) is provided with a one-way valve, the tail end of the air inlet pipe (45) extends to the surface of the bridging seat (2), and the impact air hole (44) extends to the bottom of the bridging seat (2).

2. A radially stable support roller tappet according to claim 1, characterized in that: The inside of the bridging seat (2) is provided with a through hole (21), and the through hole (21) is arranged in a staggered manner with the air inlet pipe (45).

3. A radially stable support roller tappet according to claim 1, characterized in that: The surface of the movable shield (41) is provided with a heat dissipation hole (411), and the movable shield (41) is made of alloy material.

4. A radially stable support roller tappet according to claim 1, characterized in that: The height value of the movable shield (41) is greater than the diameter of the cam roller (6), the height value of the air groove (42) is greater than the height value of the movable shield (41), and the air inlet pipe (45) is located below the piston ring (43).

5. A radially stable support roller tappet according to claim 1, characterized in that: The inside of the movable shield (41) is provided with an inwardly recessed support groove (7), one end of the connecting rod (412) is connected with a rack (74) located in the inside of the support groove (7), and the inner wall of the support groove (7) is provided with a gear rod (73) engaged with the rack (74).

6. A radially stable support roller tappet according to claim 5, characterized in that: The inner wall of the support groove (7) is slidably connected with a sealing baffle (72), the sealing baffle (72) and the inner wall of the support groove (7) form a pressure chamber (71), and the inside of the pressure chamber (71) is filled with gas.

7. A radially stable support roller tappet according to claim 6, characterized in that: The gear rod (73) and the inner wall of the support groove (7) are connected through a bearing, the gas pressure in the pressure chamber (71) in the engagement state of the gear rod (73) and the rack (74) in the initial state is equal to the external gas pressure of the shell (1), and the rack (74) is connected with the sealing baffle (72).

Images