A camshaft torsion testing device

Abstract

The present application relates to the technical field of torsion test, and discloses a camshaft torsion test device, which comprises an exhaust cam, an intake cam, a fixing base, a camshaft segment, an adapter, a first limiting piece, a second limiting piece, a connecting bolt and a nut, the camshaft segment comprises a body and a sleeve protruding from one end of the body, the exhaust cam and the intake cam are sleeved on the sleeve, the adapter is installed on the other end of the camshaft segment, the first limiting piece is used for limiting the rotation of the exhaust cam relative to the body, and the second limiting piece is used for limiting the rotation of the intake cam relative to the fixing base; the connecting bolt is threaded through the fixing base and the sleeve and is screwed with the body; the nut is screwed with the connecting bolt and is used for giving the fixing base a pre-tightening force, so that the fixing base, the intake cam, the exhaust cam and the body are tightly abutted in sequence, the adapter is connected with a torque wrench to provide a set torque value, and whether the exhaust cam and the intake cam have relatively rotated is observed to determine whether there is a use risk after installation.

Description

Technical Field

[0001] This invention relates to the field of torque testing technology, and more particularly to a camshaft torque testing device. Background Technology

[0002] During internal combustion engine operation, the opening of the intake and exhaust valves is mainly controlled by the camshaft assembly. The profile of the cams on the camshaft assembly determines the intake and exhaust timing of the valves. Camshaft assemblies are generally classified into two types based on whether the cams and shaft are integrated: integral and composite. Composite camshaft assemblies are particularly suitable for single-cylinder diesel engines. In composite camshaft assemblies, both the exhaust and intake cams are rotatably mounted on the crankshaft. Axial preload is provided by fastening components to keep the exhaust and intake cams pressed against each other along the crankshaft axis. However, there is a risk of mutual rotation between the exhaust and intake cams. If the contact surfaces of the exhaust and intake cams slip relative to each other during actual use, it can easily lead to damage to the camshaft assembly and valve train. Therefore, to ensure the safety of diesel engine operation, it is necessary to test and verify whether the exhaust and intake cams will slip before installation. However, existing technology lacks relevant testing devices. Summary of the Invention

[0003] The purpose of this invention is to provide a camshaft torque testing device to test and verify whether the exhaust cam and intake cam will slip before installation.

[0004] This invention provides a camshaft torque testing device, which includes an exhaust cam and an intake cam, and further includes:

[0005] Mounting bracket, used for mounting on the workbench;

[0006] The camshaft section includes a body and a sleeve protruding from one end of the body. The exhaust cam and the intake cam are both sleeved on the sleeve, and the body, the exhaust cam, the intake cam and the fixed seat abut against each other in sequence.

[0007] An adapter is installed at the other end of the camshaft section, and the adapter is used to connect a torque wrench;

[0008] A first limiting member is connected to the exhaust cam and the body, and the first limiting member is used to restrict the exhaust cam from rotating relative to the body;

[0009] The second limiting member connects the intake cam and the fixed seat, and the second limiting member is used to restrict the intake cam from rotating relative to the fixed seat;

[0010] A connecting bolt is provided, with a gap between the fixed seat and the sleeve, and one end of the connecting bolt is located outside the fixed seat, while the other end is threadedly connected to the body.

[0011] A nut is threadedly connected to the connecting bolt, and the nut is used to provide a preload to the fixing seat so that the fixing seat, the intake cam, the exhaust cam and the body are sequentially pressed together.

[0012] As a preferred technical solution for the camshaft torque testing device, the camshaft torque testing device further includes a washer sleeved on the connecting bolt, the washer abutting against the fixed seat, and the preload force of the nut on the fixed seat acting on the washer.

[0013] As a preferred technical solution for the camshaft torque testing device, the camshaft torque testing device further includes a plurality of adjusting bolts spaced apart along the circumferential direction of the nut, each adjusting bolt being threadedly connected to the nut, and one end of each adjusting bolt abutting against the washer.

[0014] As a preferred technical solution for the camshaft torque testing device, the fixed base is provided with multiple positioning holes, which are used to connect with external positioning components installed on the worktable.

[0015] As a preferred technical solution for the camshaft torque testing device, the fixed seat portion is sleeved on the sleeve.

[0016] As a preferred technical solution for the camshaft torque testing device, the first limiting member is a first positioning pin, and multiple first positioning pins are provided. The multiple first positioning pins are spaced apart along the circumferential direction of the exhaust cam, and the two ends of the first positioning pin are respectively inserted into the exhaust cam and the body.

[0017] As a preferred technical solution for the camshaft torque testing device, the second limiting member is a second positioning pin, and multiple second positioning pins are provided. The multiple second positioning pins are spaced apart along the circumferential direction of the intake cam, and the two ends of the second positioning pin are respectively inserted into the intake cam and the fixed seat.

[0018] As a preferred technical solution for the camshaft torque testing device, the adapter includes:

[0019] The flange has multiple through holes;

[0020] Multiple fastening bolts are provided, each corresponding to one of the multiple through holes, and the fastening bolts are threadedly connected to the body.

[0021] An external hexagonal protrusion is provided on the flange, and the external hexagonal protrusion is used to connect with a torque wrench.

[0022] As a preferred technical solution for the camshaft torque testing device, the flange is further provided with a first pin hole, the body is provided with a second pin hole, and the adapter further includes a pin, with both ends of the pin being inserted into the first pin hole and the second pin hole respectively.

[0023] As a preferred technical solution for the camshaft torque testing device, the exhaust cam is provided with a first scale mark at the end near the intake cam, and the intake cam is provided with a second scale mark at the end near the exhaust cam.

[0024] The beneficial effects of this invention are as follows:

[0025] The present invention provides a camshaft torque testing device, which includes an exhaust cam, an intake cam, a fixed seat, a camshaft section, an adapter, a first limiting member, a second limiting member, a connecting bolt, and a nut. The system includes a fixed base for mounting on a workbench, a camshaft section comprising a body and a sleeve protruding from one end of the body, both exhaust and intake cams fitted onto the sleeve, an adapter mounted on the other end of the camshaft section for connecting a torque wrench, a first limiting member connecting the exhaust cam and the body for limiting the exhaust cam's rotation relative to the body, a second limiting member connecting the intake cam and the fixed base for limiting the intake cam's rotation relative to the fixed base, a connecting bolt passing through the fixed base and the sleeve, with one end of the connecting bolt outside the fixed base and the other end threadedly connected to the body, and a nut threadedly connected to the connecting bolt for providing preload to the fixed base, so that the fixed base, intake cam, exhaust cam, and body are sequentially pressed together. A torque wrench is used to provide a set torque value, and the relative rotation of the exhaust cam and intake cam is observed to determine whether there is a risk of mutual rotation between the exhaust cam and intake cam after installation. Attached Figure Description

[0026] Figure 1 This is an isometric view of the camshaft torque testing device in an embodiment of the present invention;

[0027] Figure 2 This is an exploded view of the camshaft torque testing device in an embodiment of the present invention;

[0028] Figure 3 This is a cross-sectional view of the camshaft torque testing device in an embodiment of the present invention.

[0029] In the picture:

[0030] 1. Exhaust camshaft; 2. Intake camshaft; 3. Mounting bracket; 4. Camshaft section; 5. Adapter; 6. First locating pin; 7. Second locating pin; 8. Connecting bolt; 9. Nut; 10. Washer; 20. Adjusting bolt; 30. First graduation mark; 40. Second graduation mark;

[0031] 31. Positioning holes;

[0032] 41. Body; 42. Sleeve;

[0033] 51. Flange; 52. Fastening bolt; 53. External hexagonal protrusion; 54. Pin. Detailed Implementation

[0034] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions. Furthermore, "above," "on top of," and "over" the first feature in relation to the second feature includes the first feature directly above and diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "under," and "below" the first feature in relation to the second feature includes the first feature directly below and diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0036] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0037] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0038] In existing combined camshaft assemblies, both the exhaust cam and the intake cam are rotatably mounted on the crankshaft. An axial preload is provided by a fastening assembly to keep the exhaust cam and the intake cam pressed against each other along the crankshaft axis. However, there is a risk that the exhaust cam and the intake cam may rotate relative to each other. If the contact surfaces of the exhaust cam and the intake cam slip relative to each other during actual use of the diesel engine, it can easily lead to damage to the camshaft assembly and valve transmission mechanism. Therefore, in order to ensure the safety of diesel engine use, it is necessary to test and verify whether the exhaust cam and the intake cam will slip before installation. However, the existing technology lacks relevant testing equipment.

[0039] In this embodiment, a camshaft torque testing device is provided to test and verify whether the exhaust cam and intake cam will slip.

[0040] Specifically, such as Figures 1 to 3 As shown, the camshaft torque testing device includes an exhaust cam 1, an intake cam 2, a fixed seat 3, a camshaft section 4, an adapter 5, a first limiting component, a second limiting component, a connecting bolt 8, and a nut 9. The fixed seat 3 is used to install on the workbench (not shown in the attached drawing). The camshaft section 4 includes a body 41 and a sleeve 42 protruding from one end of the body 41. The exhaust cam 1 and the intake cam 2 are both sleeved on the sleeve 42, and the body 41, the exhaust cam 1, the intake cam 2 and the fixed seat 3 abut against each other in sequence. The adapter 5 is installed on the other end of the camshaft section 4, and the adapter 5 is used to connect a torque wrench (not shown in the attached drawing). The first limiting member connects the exhaust cam 1 and the body 41, and the first limiting member is used to limit the rotation of the exhaust cam 1 relative to the body 41. The second limiting member connects the intake cam 2 and the fixed seat 3, and the second limiting member is used to limit the rotation of the intake cam 2 relative to the fixed seat 3. The connecting bolt 8 passes through the fixed seat 3 and the sleeve 42 with a gap, and one end of the connecting bolt 8 is located outside the fixed seat 3, and the other end is threaded to the body 41. The nut 9 is threaded to the connecting bolt 8, and the nut 9 is used to give the fixed seat 3 a preload so that the fixed seat 3, the intake cam 2, the exhaust cam 1 and the body 41 abut against each other in sequence.

[0041] The camshaft torque testing device provided in this embodiment can be fixed to the workbench by the fixing base 3. A preload is applied to the fixing base 3 via the adjusting nut 9 to sequentially tighten the fixing base 3, intake cam 2, exhaust cam 1, and body 41. A set torque is applied via a torque wrench, and the relative rotation of the exhaust cam 1 and intake cam 2 is observed to determine if there are any safety hazards after installation. The magnitude of the preload can be set according to the actual force between the exhaust cam 1 and intake cam 2 after installation, and the set torque can be set based on the torque between the exhaust cam 1 and intake cam 2 after installation, combined with the lever arm of the torque wrench.

[0042] Optionally, the camshaft torque testing device also includes a washer 10 fitted onto the connecting bolt 8. The washer 10 abuts against the fixed seat 3, and the nut 9 applies a preload force to the fixed seat 3 onto the washer 10. By setting the washer 10, the force on the fixed seat 3 can be ensured to be balanced.

[0043] One method to adjust the preload is by rotating the nut 9 and moving it on the connecting bolt 8, but this method incurs a heavy workload. Therefore, in this embodiment, the camshaft torque testing device also includes multiple adjusting bolts 20 spaced apart along the circumference of the nut 9. Each adjusting bolt 20 is threaded to the nut 9, and one end of each adjusting bolt 20 abuts against a washer 10. This arrangement allows the preload to be adjusted by turning each adjusting bolt 20, distributing the preload evenly across the multiple adjusting bolts 20 and reducing the workload.

[0044] Optionally, to facilitate identification of whether the intake cam 2 and exhaust cam 1 have slipped relative to each other during the test, a first scale mark 30 is provided at the end of the exhaust cam 1 closest to the intake cam 2, and a second scale mark 40 is provided at the end of the intake cam 2 closest to the exhaust cam 1. Both the first scale mark 30 and the second scale mark 40 include circumferentially arranged scale lines and several numerical values. When the first scale mark 30 and the second scale mark 40 are misaligned relative to each other, it can be determined that the intake cam 2 and exhaust cam 1 have slipped relative to each other; when the first scale mark 30 and the second scale mark 40 are not misaligned relative to each other, it can be determined that the intake cam 2 and exhaust cam 1 have not slipped relative to each other.

[0045] Optionally, the fixed base 3 is provided with a plurality of positioning holes 31, which are used to connect with an external positioning component installed on the worktable. The external positioning component can be a bolt or a pin. Specifically, in this embodiment, the fixed base 3 is provided with two positioning holes 31, which are arranged opposite to each other on both sides of the fixed base 3.

[0046] Optionally, the fixed seat 3 is partially fitted onto the sleeve 42. It is understood that the inner diameter of the fixed seat 3 is nearly equal to the outer diameter of the sleeve 42, and the fixed seat 3 can rotate relative to the sleeve 42. This arrangement prevents relative movement between the fixed seat 3 and the camshaft segment 4 in the radial direction of the camshaft segment 4. In particular, after applying preload, guided by the sleeve 42, the fixed seat 3 can only move axially relative to the camshaft segment 4.

[0047] In this embodiment, the first limiting member is a first positioning pin 6, and multiple first positioning pins 6 are provided. The multiple first positioning pins 6 are spaced apart along the circumferential direction of the exhaust cam 1, and the two ends of the first positioning pin 6 are respectively inserted into the exhaust cam 1 and the body 41. By providing the first positioning pins 6, relative rotation between the exhaust cam 1 and the camshaft segment 4 can be prevented. In other embodiments, the first limiting member can also be a key.

[0048] In this embodiment, the second limiting member is a second positioning pin 7, and multiple second positioning pins 7 are provided. These pins 7 are spaced apart along the circumferential direction of the intake cam 2, and their two ends are respectively inserted into the intake cam 2 and the fixed seat 3. By providing the second positioning pins 7, relative rotation between the intake cam 2 and the fixed seat 3 can be prevented. In other embodiments, the second limiting member can also be a key.

[0049] Optionally, the adapter 5 includes a flange 51, fastening bolts 52, and an external hexagonal protrusion 53. The flange 51 has multiple through holes; multiple fastening bolts 52 are correspondingly inserted into the multiple through holes and are threadedly connected to the body 41; this achieves fastening between the flange 51 and the camshaft section 4. The external hexagonal protrusion 53 is located on the flange 51 and is used to connect to a torque wrench. In this embodiment, the axes of the flange 51, the external hexagonal protrusion 53, and the camshaft section 4 coincide. To avoid deviations during installation, the flange 51 also has a first pin hole, the body 41 has a second pin hole, and the adapter 5 also includes a pin 54, with both ends of the pin 54 inserted into the first pin hole and the second pin hole, respectively.

[0050] The assembly process of the camshaft torque testing device is as follows:

[0051] First, the body 41 of the camshaft section 4 is connected to the exhaust cam 1 via the first positioning pin 6, and the intake cam 2 is connected to the fixed seat 3 via the second positioning pin 7. Then, the fixed seat 3 is fitted onto the sleeve 42 of the camshaft section 4 to complete the connection between the camshaft section 4, the exhaust cam 1, the intake cam 2, and the fixed seat 3. Next, the flange 51 is fixed to the end of the camshaft section 4 via fastening bolts 52 and pins 54. Then, the connecting bolts 8 are passed through the fixed seat 3 and the sleeve 42 of the camshaft section 4 in sequence, and the connecting bolts 8 and the body 41 of the camshaft section 4 are screwed together. Then, the gasket 10 is fitted onto the connecting bolt 8, and the nut 9 is screwed onto the connecting bolt 8. Then, multiple adjusting bolts 20 are screwed onto the nut 9, and the adjusting bolts 20 press the gasket 10 against the fixed seat 3 to press the fixed seat 3, the intake cam 2, the exhaust cam 1, and the body 41 of the camshaft section 4 together in sequence. Finally, an external positioning component is installed through the positioning hole 31 on the fixed seat 3 to connect and fix the fixed seat 3 to the worktable.

[0052] The operation method of this camshaft torque testing device is as follows:

[0053] First, according to the design requirements of the combined camshaft assembly, each adjusting bolt 20 is screwed to the appropriate position, and the adjusting bolt 20, shim 10, fixing seat 3, intake cam 2, exhaust cam 1 and the body 41 of camshaft section 4 are pressed together in sequence to simulate the installation state of the combined camshaft assembly.

[0054] Then, the torque wrench is placed on the external hexagonal protrusion 53 of the adapter 5 and the torque is applied according to the torque test parameters.

[0055] Finally, using the first scale mark 30 and the second scale mark 40 as references, observe whether there will be relative slippage or loosening between the exhaust cam 1 and the intake cam 2, in order to verify the feasibility of the combined camshaft assembly design and thus ensure the safety of subsequent installation and use.

[0056] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A camshaft torque testing device, comprising an exhaust cam (1) and an intake cam (2), characterized in that, The camshaft torque testing device also includes: Fixed base (3), used for mounting on the workbench; Camshaft section (4), the camshaft section (4) includes a body (41) and a sleeve (42) protruding from one end of the body (41). The exhaust cam (1) and the intake cam (2) are both sleeved on the sleeve (42), and the body (41), the exhaust cam (1), the intake cam (2) and the fixed seat (3) abut against each other in sequence. A set torque value is provided by a torque wrench, and it is observed whether the exhaust cam (1) and the intake cam (2) have rotated relative to each other. This is to determine whether there is a risk of mutual rotation between the exhaust cam (1) and the intake cam (2) after installation. The adapter (5) is installed at the other end of the camshaft section (4) and the adapter (5) is used to connect a torque wrench; A first limiting member is connected to the exhaust cam (1) and the body (41), and the first limiting member is used to restrict the exhaust cam (1) from rotating relative to the body (41); The second limiting member connects the intake cam (2) and the fixed seat (3), and the second limiting member is used to restrict the intake cam (2) from rotating relative to the fixed seat (3); A connecting bolt (8) is inserted between the fixed seat (3) and the sleeve (42), and one end of the connecting bolt (8) is located outside the fixed seat (3), while the other end is threaded to the body (41). Nut (9) is threadedly connected to the connecting bolt (8), and the nut (9) is used to give the fixed seat (3) a preload so that the fixed seat (3), the intake cam (2), the exhaust cam (1) and the body (41) are pressed together in sequence.

2. The camshaft torque testing device according to claim 1, characterized in that, The camshaft torque testing device also includes a washer (10) sleeved on the connecting bolt (8), the washer (10) abutting against the fixed seat (3), and the nut (9) applies a preload force to the fixed seat (3) on the washer (10).

3. The camshaft torque testing device according to claim 2, characterized in that, The camshaft torque testing device also includes a plurality of adjusting bolts (20) spaced apart along the circumference of the nut (9), each adjusting bolt (20) being threadedly connected to the nut (9), and one end of each adjusting bolt (20) abutting against the gasket (10).

4. The camshaft torque testing device according to claim 1, characterized in that, The fixed base (3) is provided with a plurality of positioning holes (31), which are used to connect with an external positioning component installed on the workbench.

5. The camshaft torque testing device according to claim 1, characterized in that, The fixing seat (3) is partially sleeved on the sleeve (42).

6. The camshaft torque testing device according to claim 1, characterized in that, The first limiting member is a first positioning pin (6), and there are multiple first positioning pins (6). The multiple first positioning pins (6) are spaced apart along the circumferential direction of the exhaust cam (1). The two ends of the first positioning pin (6) are respectively inserted into the exhaust cam (1) and the body (41).

7. The camshaft torque testing device according to claim 1, characterized in that, The second limiting member is a second positioning pin (7), and multiple second positioning pins (7) are provided. Multiple second positioning pins (7) are spaced apart along the circumferential direction of the intake cam (2). The two ends of the second positioning pin (7) are respectively inserted into the intake cam (2) and the fixed seat (3).

8. The camshaft torque testing device according to claim 1, characterized in that, The adapter (5) includes: The flange (51) is provided with multiple through holes; Multiple fastening bolts (52) are provided one-to-one in the multiple through holes, and the fastening bolts (52) are threadedly connected to the body (41). An external hexagonal protrusion (53) is provided on the flange (51), and the external hexagonal protrusion (53) is used to connect with a torque wrench.

9. The camshaft torque testing device according to claim 8, characterized in that, The flange (51) is provided with a first pin hole, the body (41) is provided with a second pin hole, and the adapter (5) also includes a pin (54), the two ends of which are respectively inserted into the first pin hole and the second pin hole.

10. The camshaft torque testing device according to any one of claims 1-9, characterized in that, The exhaust cam (1) has a first scale mark (30) at one end near the intake cam (2), and the intake cam (2) has a second scale mark (40) at one end near the exhaust cam (1).

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