Equivalent device for crankshaft dynamic balance

Abstract

The invention discloses an equivalent device for crankshaft dynamic balance, which comprises two semicircular equivalent bodies, the lower ends of the equivalent bodies are planes, and the planes of the two equivalent bodies are butted to form the annular equivalent device; the inner diameter of the circular ring shape is the same as the diameter of a connecting rod journal of the crankshaft, and the circular ring shape is used for being sleeved on the connecting rod journal; the device is characterized in that a notch is formed in one side of the equivalent body and used for forming a platform below the notch, an unthreaded hole II is formed in the platform, and a screw hole I which is symmetrical to the unthreaded hole II is formed in the lower end face of the other side of the equivalent body; when the planes of the two equivalent bodies are in butt joint, locking screws penetrate through the unthreaded holes II and then are screwed in the screw holes I, so that the two equivalent bodies are assembled together; a screw hole II is formed in the arc surface of the equivalent body, and a counterweight assembly consisting of a counterweight screw and a counterweight gasket is screwed in the screw hole II; the axis of the counterweight screw points to the circle center of the circular ring shape, and the included angle between the axis of the counterweight screw and the plane of the lower end of the equivalent body is 45 degrees. A connecting rod piston assembly is simulated, the structure is simple, the cost is low, the assembly is convenient and firm, and the equivalent weight device can flexibly carry out counterweight fine adjustment through the counterweight gasket, so that the convenience and the efficiency in a dynamic balance test are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of engine manufacturing, and in particular relates to an equivalent device for dynamic balancing of a crankshaft. Background Art

[0002] A diesel engine with a crank-connecting rod mechanism as the main transmission method has reciprocating parts such as piston assemblies and valve assemblies, and parts such as crankshafts and connecting rods with unbalanced rotating masses, which cause the diesel engine to generate reciprocating inertia forces that change in size and direction alternately and rotating inertia forces that change in direction alternately. During the crankshaft manufacturing process, it is necessary to consider designing a suitable balancing block to balance the unbalanced forces and torques generated by the crankshaft shaft system. After the balancing block is installed, the dynamic balancing test of the crankshaft must be carried out with the piston-connecting rod assembly installed to ensure that the crankshaft shaft system does not generate unbalanced forces and torques to the outside. During the dynamic balancing process of the crankshaft, the piston-connecting rod assembly cannot be installed. Therefore, an equivalent device that can accurately simulate the mass of the piston-connecting rod assembly must be designed and installed on the connecting rod shaft diameter of the crankshaft. At present, there are few patents related to equivalent devices used in dynamic balancing of crankshafts. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the existing defects and provide an equivalent device for crankshaft dynamic balancing. The purpose is that the equivalent device must achieve the following functions:

[0004] 1. The crankshaft must rotate at high speed during dynamic balancing, which requires that the equivalent device and the crankshaft connecting rod journal must be securely fastened.

[0005] 2. The mass of the equivalent device must be highly consistent with the converted mass of the piston connecting rod assembly, and the mass center of the equivalent device 1 must be located at the center of the connecting rod shaft diameter mounting hole. This requires that the equivalent device should have a mass fine-tuning function.

[0006] 3. The equivalent device must achieve fine adjustment of the dynamic unbalance under constant mass.

[0007] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: an equivalent device for crankshaft dynamic balancing, comprising an equivalent body, a connecting device, a mass compensation device, and a connecting shaft. The equivalent body is a semi-ring structure entity, and a platform surface is designed on one side of the semi-ring structure; a light hole and a screw hole are designed on the joint surface of the equivalent body; after the two equivalent bodies are assembled, evenly divided threaded holes are designed on the outermost circumference of the equivalent body for the installation of counterweight screws. The connecting device is that when the two equivalent bodies are assembled on the journal, high-precision positioning pins and equal-weight screws are used for locking. The positioning pins are installed one on each side of the equivalent body for positioning the position accuracy of the repeated assembly of the equivalent body, and one (or two) locking screws are installed on each side of the equivalent body. The mass compensation device is composed of equal-weight counterweight screws and counterweight washers of different specifications. After the equivalent body is installed, the counterweight washers of different weights are pressed with counterweight screws, and the counterweight washers can be adjusted according to the imbalance. The connecting shaft is composed of circular shafts of the same size on both sides and an equivalent body assembly shaft in the middle. One end of the connecting shaft is designed with a threaded hole connected to a universal joint, which is convenient for connection with a dynamic balancing machine to perform a dynamic balancing test on the equivalent device, so that the equivalent device can maintain 360° dynamic balance.

[0008] The equivalent device can accurately simulate the mass of the piston-connecting rod assembly. The equivalent device will be installed on the connecting rod journal of the crankshaft, and together with the balancing block, the unbalance test of the crankshaft components will be carried out, so that the moving parts of the crankshaft of the diesel engine can maintain a state of dynamic balance during operation. The equivalent device must achieve a dynamic unbalance of less than 1g under constant mass. The equivalent device consists of two semi-annular equivalent bodies, which are positioned by pins and fixed by screws, and the unbalance is adjusted by configuring screws and counterweight washers. The counterweight screws of the equivalent device are evenly distributed on the outer circle of the device, and the mass of the counterweight screws is consistent. The counterweight washers of the equivalent device adopt different mass specifications and are installed on the counterweight screws with equal mass.

[0009] The balancing process of the equivalent device. The first step is to install the equivalent device on the balancing connecting shaft. The second step is to weigh the counterweight screws and counterweight washers of the same mass. The third step is to install the configured counterweight screws and counterweight washers on the equivalent body. The fourth step is to connect the balancing connecting shaft and the dynamic balancing tester. The fifth step is to start the balancing test to determine the imbalance and position. The sixth step is to adjust the counterweight washers and start the balancing test again until the imbalance of the equivalent body parts is less than 1g. The seventh step is to tighten the configuration screws. The eighth step is to remove the equivalent body to complete the counterweighting of the equivalent device.

[0010] The equivalent device is installed on a dynamic balancing tester, and the tester is started to test the unbalanced amount of the equivalent body within 1g, and the balancing process of the equivalent body is completed. If the unbalanced amount is outside 1g, it is necessary to adjust the position and number of the counterweight gaskets according to the test results, and repeat the test until the unbalanced amount is within 1g. After completing the first dynamic balancing test, the equivalent device is reversed 180°, and then the dynamic balancing test is performed again within 1g. If the requirements are not met after the reversal, the counterweight and balancing test needs to be repeated.

[0011] The equivalent device is used. The first step is to install the equivalent device with the counterweight on each crank arm pin. The second step is to manually move the crankshaft to eliminate interference. The third step is to connect the crankshaft to the dynamic balancing tester. The fourth step is to start the balancing tester and perform a dynamic balancing test. The fifth step is to remove the equivalent device after completing the dynamic balancing test of the crankshaft.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows.

[0013] The equivalent device of the present invention is designed with a connecting shaft, which can be connected to a dynamic balancing machine through the connecting shaft to adjust the dynamic unbalance amount of the equivalent device.

[0014] The equivalent device of the present invention accurately simulates the mass of the piston-connecting rod assembly. When performing dynamic balancing of the crankshaft, it highly restores the working state of the crankshaft on the engine. Through dynamic balancing, the imbalance of the crankshaft is reduced to a reasonable range, ensuring that the crankshaft basically generates no force and torque to the outside during operation, making the engine run more smoothly and with higher reliability.

[0015] The equivalent device of the present invention adopts four groups of counterweight gaskets of different specifications to fine-tune the unbalance amount, which greatly improves the dynamic balancing accuracy of the crankshaft. The counterweight gaskets are easy to disassemble and assemble, and have strong operability.

[0016] The equivalent device of the present invention adopts a fully symmetrical design and overall balancing treatment to ensure that the mass center of the equivalent device is at the center of the mounting hole. When installed on the crankshaft connecting rod diameter, the center of mass of the equivalent device coincides with the center of mass of the crankshaft connecting rod diameter, highly restoring the working state of the crankshaft on the engine.

[0017] The manufacturing method of the present invention makes the equivalent device modularly designed. By properly adjusting the inner hole, thickness and outer circle size of the equivalent device, it can be applied to the dynamic balancing of crankshafts of various types of engines. Its design concept has a high value of promotion and application.

[0018] The invention assembles two identical equivalent bodies to form an equivalent device, thereby reducing the types of components, lowering the manufacturing difficulty and reducing the cost.

[0019] In summary, the equivalent device of the present invention simulates a connecting rod piston assembly, which has a simple structure, low cost, easy and firm assembly, and the equivalent device can flexibly fine-tune the weight through a weight gasket, thereby improving convenience and efficiency in dynamic balancing tests. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic outline diagram of an equivalent device 1 according to an embodiment of the present invention;

[0021] Figure 2 is a schematic structural diagram of an equivalent device 1 according to an embodiment of the present invention;

[0022] Figure 3 yes Figure 2 Left view of

[0023] Figure 4 It is a structural diagram and technical weight parameters of a weight balancing gasket according to an embodiment of the present invention;

[0024] Figure 5 Schematic diagram of the structure of the screw hole II of the equivalent body of the embodiment of the present invention;

[0025] Figure 6 is a schematic structural diagram of a blind hole of an equivalent body of an embodiment of the present invention;

[0026] Figure 7 is a schematic diagram of a dynamic balance self-test structure of an equivalent device according to an embodiment of the present invention;

[0027] Figure 8 It is a schematic structural diagram of a measuring device according to an embodiment of the present invention installed on a crankshaft for testing.

[0028] In the figure: 1. equivalent device; 2. equivalent body; 21. notch; 22. platform; 3. counterweight screw; 4. counterweight gasket; 5. locking screw; 6. locating pin; 7. light hole I; 8. light hole II; 9. blind hole; 10. screw hole I; 11. screw hole II; 12. connecting shaft; 13. crankshaft. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0030] See also Figure 1-8The present invention provides a technical solution: an equivalent device for dynamic balancing of a crankshaft, the equivalent device for dynamic balancing of a crankshaft comprises an equivalent body 2, a counterweight screw 3, a counterweight gasket 4, a locking screw 5, and a positioning pin 6. The equivalent device 1 is installed on the connecting rod journal of the engine crankshaft 13, and the unbalance amount of the crankshaft assembly is adjusted on a dynamic balancing test machine by accurately simulating the mass of the connecting rod piston assembly, thereby eliminating the adverse effects of the crankshaft assembly on the working state of the engine when rotating at high speed. The equivalent body 2 in the equivalent device 1 is designed as a semi-annular equivalent body 2 for the convenience of on-site installation, and a light hole Ⅰ7, a light hole Ⅱ8, a blind hole 9, and a screw hole Ⅰ10 are designed on the joint surface of the equivalent body 2 for installation and positioning. The counterweight screw 3 is used to install the counterweight gasket 4 on the screw hole Ⅱ11, which is used to adjust the dynamic balance state of the equivalent device 1 under constant mass and fine-tune the counterweight mass.

[0031] as follows Figure 2 , Figure 3 As shown, in the present invention, the structural dimensions of the equivalent device are as follows:

[0032] The inner hole size R1 of the equivalent device is the nominal size of the crankshaft connecting rod journal diameter; the width B of the equivalent device is the width of the straightness part of the crankshaft connecting rod journal; in order to ensure that the installation process of the equivalent device is smooth and there is no loose state on the connecting rod journal, a gap of size A is designed on the joint surface of the equivalent device; the outer circle size R2 of the equivalent device is determined according to the mass value of the piston connecting rod assembly.

[0033] It can be seen that each equivalent body 2 is connected to two counterweight assemblies, which are symmetrically distributed on the left and right. The increased number of counterweight assemblies facilitates dynamic balancing weight adjustment. Although the locking screw 5 also has a positioning function, the positioning accuracy is insufficient. A pair of positioning pins 6 are provided; the positioning pin 6 passes through the light hole I set on the platform 22 and is inserted into the blind hole 9 preset in the equivalent body 2; it ensures that the two equivalent bodies 2 will not be skewed during the assembly process, and the assembly process avoids the generation of unbalanced amount. Under the action of the positioning pin 6, when the equivalent device 1 is mounted on the connecting rod journal, a gap is left between the planes where the two equivalent bodies 2 are docked, that is, the gap A, which can ensure that the two equivalent bodies clamp the connecting rod journal of the crankshaft, and the fixation is more firm and does not affect the dynamic balance. Preferably, the axis of the positioning pin 6 is coplanar with the cross section of the center of the equivalent body 2; two locking screws 5 are connected to each platform 22, and are symmetrically distributed on the left and right with the axis of the positioning pin 6 as the reference. The positioning is more accurate, the weight distribution is more uniform, the number of locking screws 5 is more, and the fixation is more firm.

[0034] In the present invention, the weight balancing process of the equivalent device is as follows:

[0035] An equivalent device for crankshaft dynamic balancing includes two equivalent bodies 2, four counterweight screws 3, a plurality of counterweight washers 4, two locking screws 5, and two positioning pins. In order to accurately simulate the mass of the piston-connecting rod assembly, the total mass of the equivalent device must be the same as the mass of the piston-connecting rod assembly. The total mass of the two equivalent bodies 2, four counterweight screws 3 of equal mass, two locking screws 5, and two positioning pins is weighed on a balance, and counterweight washers 4 are added according to the weighed mass until the total mass of the equivalent device is equal to the mass of the piston-connecting rod assembly.

[0036] as follows Figure 7 As shown, in the present invention, the dynamic balancing process of the equivalent device is as follows:

[0037] First, install the positioning pin 6 in the blind hole 9 of the equivalent body 2, and then install the equivalent body 2 on the connecting shaft 12; the locking screw 5 passes through the light hole II8 and connects to the screw hole I10, and pre-tightens; adjust the equivalent device 1 to the axial center position of the connecting shaft, tighten the locking screw 5; divide the counterweight gasket into 4 parts, and install them on the equivalent device using the counterweight screw 3. Connect the connecting shaft 12 to the dynamic balancing test machine, start the balancing test, and adjust the position of the counterweight gaskets of different specifications to make the unbalance of the equivalent device within 1g.

[0038] as follows Figure 8 As shown, in the present invention, the use process of the equivalent device is as follows:

[0039] First, hang the crankshaft 13 on the bracket, and install the equivalent device 1 configured in the previous step on the connecting rod journal of the crankshaft 13. Use the positioning pin 6 to fix the relative position of the two equivalent bodies 2, and then use the locking screw 5 to pre-tighten the two equivalent bodies. Use the tool to adjust the equivalent device 1 to the middle position of the straight part of the crankshaft 13; tighten the locking screw 5 until the equivalent device 1 does not slide. Install the equivalent device 1 on the connecting rod journal one by one according to this step. After the installation is completed, start the balancing test to complete the dynamic balancing of the crankshaft 13.

[0040] The equivalent device 1 of the present invention is designed with a connecting shaft 12, which can be connected to a dynamic balancing machine through the connecting shaft 12 to adjust the dynamic unbalance amount of the equivalent device.

[0041] The equivalent device 1 of the present invention accurately simulates the mass of the piston-connecting rod assembly. When performing dynamic balancing of the crankshaft 13, it highly restores the working state of the crankshaft 13 on the engine. Through dynamic balancing, the imbalance of the crankshaft 13 is reduced to a reasonable range, ensuring that the crankshaft 13 basically does not generate any force and torque to the outside during operation, making the engine run more smoothly and with higher reliability.

[0042] The equivalent device 1 of the present invention uses four groups of counterweight washers of different specifications to fine-tune the imbalance, which greatly improves the dynamic balancing accuracy of the crankshaft 13. The counterweight washers 4 are easy to assemble and disassemble and have strong operability.

[0043] The equivalent device 1 of the present invention adopts a fully symmetrical design and overall balancing treatment to ensure that the mass center of the equivalent device is at the center of the mounting hole. When installed on the crankshaft connecting rod diameter, the center of mass of the equivalent device coincides with the center of mass of the crankshaft connecting rod diameter, highly restoring the working state of the crankshaft on the engine.

[0044] The manufacturing method of the present invention makes the equivalent device 1 modularly designed. By properly adjusting the inner hole, thickness and outer circle size of the equivalent device, it can be applied to the dynamic balancing of crankshafts of various types of engines. Its design concept has a high value of promotion and application.

[0045] The manufacturing method of the equivalent device 1 of the present invention makes the mass center and the geometric center of the equivalent device 1 coincide with each other, thereby ensuring that the mass of the equivalent device 1 in each radial direction is equal based on the geometric center.

[0046] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An equivalent device for crankshaft dynamic balancing, comprising two semi-circular equivalent bodies (2), the lower ends of the equivalent bodies (2) being flat, the flat surfaces of the two equivalent bodies (2) being butted together to form an equivalent device (1) in the shape of a circular ring; the inner diameter of the circular ring is the same as the diameter of the connecting rod journal of the crankshaft (13), and is used to be mounted on the connecting rod journal; characterized in that: A notch (21) is provided on one side of the equivalent body (2), and a platform (22) is formed below the notch (21). A light hole II (8) is provided on the platform (22). A screw hole I (10) corresponding to the light hole II (8) is provided on the lower end surface of the other side of the equivalent body (2); when the planes of the two equivalent bodies (2) are butted, a locking screw (5) is passed through the light hole II (8) and then screwed into the screw hole I (10), so that the two equivalent bodies (2) are assembled together; A screw hole II (11) is provided on the arc surface of the equivalent body (2) for screwing a weight assembly into the screw hole II (11); the weight assembly comprises a weight screw (3) and a configuration gasket (4) sleeved on the weight screw (3); the axis of the weight screw (3) points to the center of the circular ring shape and forms an angle of 45° with the plane of the lower end of the equivalent body (2).

2. The equivalent device for crankshaft dynamic balancing according to claim 1, characterized in that: Each of the equivalent bodies (2) is connected to two counterweight assemblies, which are symmetrically distributed on the left and right.

3. The equivalent device for crankshaft dynamic balancing according to claim 1, characterized in that: It also includes a pair of positioning pins (6); the positioning pins (6) penetrate through the light holes I (7) provided on the platform (22) and are then inserted into the blind holes (9) preset on the equivalent body (2).

4. The equivalent device for crankshaft dynamic balancing according to claim 3, characterized in that: When the equivalent device (1) is mounted on the connecting rod journal, a gap is left between the butting planes of the two equivalent bodies (2).

5. The equivalent device for crankshaft dynamic balancing according to claim 3, characterized in that: The axis of the positioning pin (6) is coplanar with the cross section at the center of the equivalent body (2); two locking screws (5) are connected to each platform (22) and are symmetrically distributed with the axis of the positioning pin (6) as a reference.

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