Balancing shaft machining device and machining method

Abstract

This invention relates to the field of balance shaft machining technology, and provides a balance shaft machining device and method. The device includes a frame with a rotary spindle and a centering fixture. The centering fixture can center and clamp the shaft head of the balance shaft and drive the balance shaft to rotate as a whole. A support frame is disposed on one side of the frame, and a swing bracket is rotatably mounted on the support frame. The swing bracket can swing and move between a lifting position and a working position. The balance frame has a main body and a clamping assembly. The clamping assembly can clamp onto the outer wall of the balance shaft cylinder, so that the balance frame can rotate with the balance shaft. The balance frame and the shaft support on the balance shaft are respectively located on both sides of the cylinder, so that the center of mass of the balance shaft and the balance frame as a whole can be located on the axis of the balance shaft. This invention achieves rapid installation of the balance frame through the swing bracket and adjusts the center of mass of the balance shaft as a whole through the balance frame, solving the technical problem that existing rotary machine tools cannot perform machining with a shaft support.

Description

Technical Field

[0001] This invention relates to the field of balance shaft machining technology, specifically to a balance shaft machining apparatus and machining method. Background Technology

[0002] The balance shaft is a key mechanical component in an internal combustion engine used to counteract reciprocating and rotational inertial forces, reduce engine vibration, and improve running smoothness. It mainly consists of a shaft head, a shaft tube, and a shaft bracket. The core principle is to use the shaft bracket as an eccentric weight to make the shaft tube rotate synchronously with the crankshaft, generating an inertial force that is opposite in direction and equal in magnitude to the original vibration of the engine, thus achieving "force balance".

[0003] Because of the presence of the bearing on the balance shaft, the center of gravity of the balance shaft is not on the axis of the shaft tube. This means that the balance shaft cannot be directly placed on a rotary machining tool where the workpiece rotates. Otherwise, the eccentricity of the balance shaft can easily damage the machine tool spindle and fixture. Furthermore, the eccentric vibration can cause poor surface finish or tool damage.

[0004] In existing technology, the shaft head, shaft tube, and shaft bracket are processed separately. Specifically, the shaft head is first rough-machined, then the mating surface between the shaft head and the shaft tube is finish-machined before assembly with the shaft tube. The shaft head and shaft tube are then welded together, and the outer diameter of the shaft head is finished using a machine tool. Finally, the shaft bracket is welded onto the shaft tube to complete the machining of the entire balance shaft. However, this method, which involves finishing the connection surfaces of the shaft head and shaft tube before welding, and then finishing the shaft head before welding it to the shaft bracket, results in two welding deformations, leading to two dimensional offsets in the shaft head. The cumulative effect of these two dimensional offsets results in a final pass rate of less than 10% for the balance bracket. Summary of the Invention

[0005] To overcome the above-mentioned defects, embodiments of the present invention provide a balance shaft machining device and machining method, which solves the technical problem that workpiece rotary machine tools cannot perform machining with a shaft support in the prior art.

[0006] A balance shaft machining device, comprising:

[0007] The frame is equipped with a rotary spindle and a centering clamp, which can center and hold the shaft head of the balance shaft and drive the balance shaft to rotate as a whole.

[0008] A support frame is provided on one side of the frame body, and a swing bracket is swayingly provided on the support frame;

[0009] A balance frame includes a main body and a clamping assembly. The clamping assembly is used to clamp the balance shaft on the outer periphery of the shaft cylinder so that the balance frame can rotate with the balance shaft. The balance frame and the shaft bracket on the balance shaft are located on both sides of the shaft cylinder, respectively.

[0010] The swing support is used to support the balance frame. When the clamping assembly clamps the balance shaft, the swing support can swing away from the balance frame so that the balance frame rotates with the balance shaft.

[0011] As a further technical solution, the main body is provided with a weight adjustment box, and several mass adjustment blocks are snapped into the weight adjustment box to match the mass of the balance frame and the shaft frame.

[0012] As a further technical solution, a movable component for moving the support frame is also included, the movable component comprising:

[0013] A sliding frame is slidably disposed on one side of the frame body, and the sliding direction of the sliding frame is parallel to the axial direction of the rotary spindle;

[0014] A lifting frame is mounted on the sliding frame, and a support frame is mounted on the lifting frame.

[0015] As a further technical solution, the clamping assembly includes:

[0016] The rotating clamp has two rods, both of which are rotatably mounted on the main body. The two rotating clamps can rotate towards each other to clamp the upper and lower sides of the shaft cylinder.

[0017] An auxiliary clamping rod is rotatably disposed at one end of the rotating clamping rod away from the rotation axis. The auxiliary clamping rod can rotate and extend outward from the rotating clamping rod to cooperate with the rotating clamping rod to clamp the side of the shaft cylinder.

[0018] As a further technical solution, a groove is provided at the end of the rotating clamping rod away from the rotation axis, and the auxiliary clamping rod can slide into the groove. The auxiliary clamping rod has a straight groove through hole, and the clamping assembly further includes:

[0019] An extension frame is provided at the end of the rotating clamp rod away from the axis and extends along the length of the rotating clamp rod. A limit shaft is provided at the end of the extension frame away from the rotating clamp rod. The limit shaft is located in the straight groove through hole so that the auxiliary clamp rod can rotate around the limit shaft after sliding away from the slide groove.

[0020] A locking piece is slidably disposed on the limiting shaft. The locking piece can slide close to the auxiliary clamping rod and can abut against the side wall of the auxiliary clamping rod to lock the rotation of the auxiliary clamping rod.

[0021] As a further technical solution, the extension frame is composed of elastic plates, the extension frame can elastically approach the auxiliary clamping rod, the limiting shaft is a screw, the limiting shaft passes through the extension frame along the deformation direction of the extension frame, and the two ends of the limiting shaft that pass through the extension frame are respectively threadedly connected to two locking nuts, the two locking nuts can rotate to compress the extension frame to elastically deform and push the locking plates closer to the auxiliary clamping rod;

[0022] The auxiliary clamping rod has several locking holes, and the locking plate has several protrusions that are adapted to the locking holes. After the locking plate slides close to the auxiliary clamping rod, the protrusions can enter the locking holes to restrict the rotation of the auxiliary clamping rod.

[0023] As a further technical solution, a drive assembly for driving the rotating clamp rod to rotate is also included, the drive assembly comprising:

[0024] A wedge-shaped pusher is slidably disposed on the main body for approaching or moving away from the shaft cylinder; the wedge-shaped pusher has an inclined pushing surface for pushing the rotating clamp rod to rotate.

[0025] A push rod is disposed on the wedge-shaped push block and extends between the two rotating clamping rods. The push rod is able to approach the shaft cylinder and abut against the outer wall of the shaft cylinder under the drive of the wedge-shaped push block.

[0026] As a further technical solution, the wedge-shaped pusher has a driving through hole, the inner wall of the driving through hole has a spiral slide, and the driving assembly further includes:

[0027] A rotating rod is rotatably mounted on the main body and located within the drive through hole. The outer wall of the rotating rod has a push post adapted to the spiral slide. The push post is located within the spiral slide so that the rotation of the rotating rod can drive the wedge-shaped push block to slide.

[0028] A rotation drive device is slidably mounted on the support frame, and the rotation drive device can slide close to one end of the rotation rod and drive the rotation rod to rotate.

[0029] A tightening bolt is threaded onto the main body, and the tightening bolt is able to approach the rotating rod radially from the rotating rod and tighten the rotating rod.

[0030] A method for machining a balance shaft, comprising machining a balance shaft using the aforementioned balance shaft machining device, including:

[0031] S10, rough machining of the shaft head, assembly and welding of the shaft head and shaft cylinder, and then welding and assembling of the shaft bracket onto the shaft cylinder to obtain the balance shaft blank;

[0032] S20, using a machining device to perform precision machining on the outer diameter of the shaft head.

[0033] As a further technical solution, S20 includes:

[0034] S21, Place the balance frame onto the swing support;

[0035] S22, assemble the balance shaft blank onto the centering fixture, adjust the mass of the balance frame according to the mass of the shaft frame, and move the balance frame to a position symmetrical to the shaft frame;

[0036] S23, clamp the shaft cylinder using the clamping assembly, and then rotate the swing support away from the balance frame;

[0037] S24, Start the rotary spindle to perform precision machining on the shaft head.

[0038] The beneficial effects of this invention are as follows:

[0039] In this invention, a counterweight-calculated balance frame is fixed to one side of the balance shaft using a clamping assembly, ensuring that the center of mass of the balance shaft and the balance frame as a whole is located on the axis of the balance shaft. This effectively solves the technical problem in existing technologies where rotary workpiece machine tools cannot perform machining with a shaft support. It avoids damage to the machine tool spindle and fixtures caused by balance shaft eccentricity, and also reduces the problems of low surface finish or tool damage due to eccentric vibration, ensuring the normal operation of the machining equipment and the quality of machining.

[0040] Compared to existing technologies that use hoisting to install balance frames, this device achieves rapid installation of the balance frame through a swing bracket. Hoisting installation requires the use of overhead cranes or other lifting equipment, and the position and attitude of the balance frame must be controlled during the hoisting process. This operation is complex and time-consuming, with each installation potentially taking 5-10 minutes or even longer. In contrast, this device simply places the balance frame on the supporting plane of the swing bracket, and the installation is completed by a simple swing of the bracket. The entire process takes only 1-2 minutes, improving the installation efficiency of the balance frame, reducing auxiliary processing time, and further enhancing overall processing efficiency. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are merely some exemplary embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the exemplary embodiments of the present invention and these drawings without any creative effort.

[0042] Figure 1 This is a schematic diagram of the overall structure of the balance shaft;

[0043] Figure 2This is a schematic diagram of the overall structure of one embodiment of the present invention;

[0044] Figure 3 for Figure 2 Enlarged structural diagram at point A in the middle;

[0045] Figure 4 for Figure 2 A side view of the structure in the embodiment;

[0046] Figure 5 for Figure 4 Enlarged structural diagram at point B;

[0047] Figure 6 This is a schematic diagram of the overall structure of the balance frame;

[0048] Figure 7 This is a schematic diagram of the overall structure of the balance frame from another angle;

[0049] Figure 8 for Figure 7 Schematic diagram of the cross-sectional structure along the CC direction;

[0050] Figure 9 for Figure 8 Enlarged structural diagram at point D;

[0051] Figure 10 This is a schematic diagram of the auxiliary clamping rod structure;

[0052] Figure 11 for Figure 8 Enlarged structural diagram at point E;

[0053] Figure 12 This is a schematic diagram of the balancer in the clamped state.

[0054] Figure 13 This is a schematic diagram of the balance frame clamping state and the shaft cylinder structure;

[0055] In the diagram: 01, balance shaft; 011, shaft head; 012, shaft sleeve; 013, shaft bracket.

[0056] 100. Frame, 110. Rotary spindle, 120. Centering fixture.

[0057] 200. Support frame; 210. Swinging bracket;

[0058] 300. Balance frame; 310. Main body; 320. Clamping assembly; 321. Rotating clamping rod; 3211. Slide groove; 322. Auxiliary clamping rod; 3221. Straight slot through hole; 3222. Locking hole; 323. Extension frame; 324. Locking piece; 3241. Protrusion; 325. Limiting shaft.

[0059] 400. Adjust the weight box.

[0060] 500. Moving component; 510. Sliding frame; 520. Lifting frame.

[0061] 610. Wedge-shaped push block; 611. Inclined push surface; 612. Drive through hole; 613. Spiral slide; 620. Push rod; 630. Rotating rod; 631. Push column; 640. Rotation drive device; 650. Tightening bolt. Detailed Implementation

[0062] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it.

[0063] To keep the drawings concise, each drawing only schematically shows the parts relevant to the invention; these do not represent the actual structure of the product. Furthermore, for ease of understanding, in some drawings, only one of components with the same structure or function is schematically shown, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one," and "several" includes "two" and "more than two."

[0064] In this document, 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 fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0065] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0066] In the description of this embodiment, terms such as "upper," "lower," "left," and "right" are based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of description and simplification of operation, and are not intended to 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 present invention.

[0067] Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0068] like Figures 1-13 As shown, a balance shaft machining device according to an embodiment of the present invention is illustrated, including a frame 100, a support frame 200, and a balance frame 300. A rotary spindle 110 and a centering fixture 120 are mounted on the frame 100. The centering fixture 120 can center and clamp shaft-like parts and drive them to rotate for machining. The frame 100, rotary spindle 110, and centering fixture 120 as a whole can be a workpiece rotary machine tool, such as a lathe or grinding machine.

[0069] The support frame 200 is located on one side of the frame 100, maintaining a certain distance from the frame 100, and is fixed to the ground or other foundation structure by bolts or welding, providing stable support for the swing bracket 210. The swing bracket 210 is rotatably mounted on the support frame 200 via a horizontally arranged shaft, allowing the swing bracket 210 to swing in a vertical plane. The swing bracket 210 is shaped like a cantilever, with one end connected to the shaft and the other end being a free end, where a lifting plane is provided. When the swing bracket 210 swings to the lifting position, the lifting plane is horizontal, capable of supporting the balance frame 300; when swinging to the working position, the swing bracket 210 moves away from the balance frame 300, without hindering the balance frame 300 from rotating with the balance shaft 01. The rotating bracket is driven by an independent rotation drive device 640, which can be a servo motor and drives the swing bracket 210 to rotate via gear meshing, chain drive, or synchronous belt drive.

[0070] The main body 310 of the balance frame 300 is a frame structure with a certain mass, and the clamping assembly 320 is mounted on the main body 310. The clamping assembly 320 can take various forms, such as clamping blocks or jaws, and is not limited here. When the clamping assembly 320 clamps the outer wall of the balance shaft 01's cylinder 012, the balance frame 300 can rotate with the balance shaft 01. The balance frame 300 is installed on one side of the balance shaft 01's cylinder 012, while the shaft bracket 013 is located on the other side of the cylinder 012. The mass and position of the balance frame 300 are determined through a counterweight calculation method, ensuring that the center of mass of the balance shaft 01 and the balance frame 300 as a whole is located on the axis of the balance shaft 01.

[0071] First, the balance shaft 01 is placed near the frame 100, and the shaft head 011 of the balance shaft 01 is centered and clamped by the centering clamp 120. At this time, the balance frame 300 is placed on the swing support 210 of the support frame 200, with the swing support 210 in a supporting position and the supporting plane supporting the balance frame 300. Next, the clamping assembly 320 clamps the outer wall of the shaft cylinder 012 of the balance shaft 01, and the swing support 210 swings away from the balance frame 300, so that the balance frame 300 remains on one side of the shaft cylinder 012 due to the clamping force of the clamping assembly 320. Subsequently, the swing support 210 continues to rotate away from the balance frame 300, avoiding the rotation path of the balance frame 300, so that the balance frame 300 can rotate together with the balance shaft 01. After the balance shaft 01 is processed, the operator can control the rotation speed of the rotary spindle 110 to 10 r / min, and then control the rotating bracket to rotate back to the lifting position. After the balance frame 300 rotates to a position that can be lifted by the rotating bracket, the clamping assembly 320 releases the balance shaft 01, so that the balance shaft 01 can be removed from the centering fixture 120, making it convenient to replace another balance shaft 01 for processing.

[0072] By fixing the counterweight-calculated balance frame 300 to one side of the balance shaft 01 using the clamping assembly 320, the center of gravity of the balance shaft 01 and the balance frame 300 as a whole is located on the axis of the balance shaft 01. This effectively solves the technical problem in the prior art that rotary workpiece machine tools cannot perform machining with the shaft frame 013. It avoids damage to the machine tool spindle and fixtures caused by the eccentricity of the balance shaft 01, and also reduces the problems of low surface finish or tool damage caused by eccentric vibration, ensuring the normal operation of the machining equipment and the machining quality.

[0073] Compared to the existing method of hoisting and installing the balance frame 300, this device achieves rapid installation of the balance frame 300 through the swing support 210. The hoisting installation method requires the use of cranes or other hoisting equipment, and the position and attitude of the balance frame 300 must be controlled during the hoisting process. This operation is complex and time-consuming, with each installation potentially taking 5-10 minutes or even longer. In contrast, this device simply places the balance frame 300 on the supporting plane of the swing support 210, and the installation of the balance frame 300 is completed by simply swinging the swing support 210. The entire process takes only 1-2 minutes, improving the installation efficiency of the balance frame 300, reducing auxiliary processing time, and further improving overall processing efficiency.

[0074] Furthermore, to accommodate the processing requirements of different mass shaft supports 013, a weight adjustment box 400 is welded or bolted to the main body 310. The weight adjustment box 400 is typically cuboid or cube-shaped, and has several slots inside. These slots are evenly distributed along the length or width of the weight adjustment box 400, and are rectangular in shape. Their width and depth are adapted to the size of the mass adjustment block to ensure that the mass adjustment block can be tightly engaged in the slot. Optionally, the slot can be connected to the mass adjustment block by interference fit, or it can be secured by a flexible rubber block, with a baffle threaded at the slot inlet to prevent the mass adjustment block from flying out of the slot during the rotation of the main body 310.

[0075] The mass adjustment block is manufactured according to the dimensions of the slot, and is usually rectangular. It is made of a high-density, uniform metal, such as cast iron or lead, to provide effective mass adjustment. Various models of mass adjustment blocks are available to meet different requirements.

[0076] By setting an adjusting box 400 and a mass adjustment block on the main body 310 of the balance frame 300, the mass of the balance frame 300 can be quickly and flexibly adjusted to precisely match the shaft frames 013 of different masses. In actual production, the processing of the same batch of balance shafts 01 only requires adjusting the weight of the adjusting box once.

[0077] Furthermore, to accommodate the different positions of the shaft bracket 013 on the shaft cylinder 012 caused by the different sizes of the balance shaft 01, a moving component is also included. This moving component can drive the support frame 200 to move. The moving component includes a sliding frame 510 and a lifting frame 520. The sliding frame 510 has a vertical, elongated frame structure, and its sliding direction is parallel to the axis of the rotary main shaft 110. The sliding frame 510 is located on one side of the frame 100, and a linear guide rail and a slider assembly are installed on the ground on one side of the frame 100. The linear guide rail is fixed to the ground with bolts, and the slider is installed at the bottom of the sliding frame 510, cooperating with the linear guide rail to allow the sliding frame 510 to slide along the axis of the rotary main shaft 110.

[0078] To drive the sliding frame 510 to slide, an electric screw drive mechanism can be used. One end of the electric screw is connected to the output shaft of the motor via a coupling, and the other end is connected to the sliding frame 510 via a nut. When the motor starts, the screw rotates, causing the nut and the connected sliding frame 510 to slide along the linear guide rail.

[0079] The lifting frame 520 is mounted on the sliding frame 510. It can employ a scissor lift structure or a screw-nut lift structure. Taking the screw-nut lift structure as an example, screws are installed on both sides of the sliding frame 510, with the upper and lower ends of the screws fixed to the sliding frame 510 via bearings. Nut seats that mate with the screws are provided on both sides of the lifting frame 520, and the nut seats are threadedly connected to the screws. When the motor drives the screws to rotate, the nut seats cause the lifting frame 520 to move up and down along the axis of the screws, thereby achieving the lifting function.

[0080] The support frame 200 is fixed to the lifting frame 520, and the connection is ensured to be firm by bolts or welding. In this way, when the sliding frame 510 slides along the axis of the rotary spindle 110, and when the lifting frame 520 moves up and down, the support frame 200 can move accordingly, thereby driving the swing support 210 and the balance frame 300 on it to adjust their positions to meet the processing requirements of balance shafts 01 of different sizes.

[0081] Furthermore, to improve the stability of the clamping assembly 320 during the rotation of the balance shaft 01, the clamping assembly 320 includes a rotating clamping rod 321 and an auxiliary clamping rod 322. The rotating clamping rod 321 is rotatably mounted on the main body 310 of the balance frame 300 via bearings. The two rotating clamping rods 321 are symmetrically distributed on both sides of the balance shaft 01 cylinder 012, and their rotation axes are parallel to the rotation axis of the rotary spindle 110. This ensures that when clamping the balance shaft 01 cylinder 012, the direction of the force is the same as the radial direction of the balance shaft 01, which is more conducive to the rotating clamping rod 321 clamping the balance shaft 01. The main body 310 of the rotating clamping rod 321 has a rod-shaped structure, and the length of the rotating clamping rod 321 should be greater than the vertical distance from the rotation axis of the rotating clamping rod 321 to the axis of the rotary spindle 110. The auxiliary clamping rod 322 is rotatably mounted on the end of the rotating clamping rod 321 away from the rotation axis via a pin, and its rotation axis is parallel to the rotation axis of the rotating clamping rod 321. The auxiliary clamping rod 322 is rod-shaped and its length is 1 / 3 to 1 / 2 of the length of the rotating clamping rod 321. After the rotating clamping rod 321 rotates close to the balance shaft 01 cylinder 012 and clamps, the operator can manually drive the auxiliary clamping rod 322 to rotate around the pin shaft, so that the auxiliary clamping rod 322 rotates to press against another point on the cylinder 012, further enhancing the stability of the clamping.

[0082] The rotating clamping rod 321 and the auxiliary clamping rod 322 clamp the balance shaft 01 cylinder 012 from multiple points. Compared with a single clamping method, it can better resist the various forces generated during the rotation of the balance shaft 01, enhance the stability of the clamping assembly 320 during the rotation of the balance shaft 01, effectively prevent the balance frame 300 from loosening or falling off during processing, and improve the safety and reliability of processing.

[0083] Furthermore, to prevent the auxiliary clamping rod 322 at the front end of the rotating clamping rod 321 from affecting the assembly and disassembly of the balance shaft 01 on the centering fixture 120 due to its long extension distance, a groove 3211 is machined along the length of the rotating clamping rod 321 at the end away from the rotation axis. The groove 3211 is rectangular in shape, and its width and depth are designed according to the dimensions of the auxiliary clamping rod 322 to ensure that the auxiliary clamping rod 322 can slide smoothly within the groove 3211.

[0084] The auxiliary clamping rod 322 has a straight slotted through hole 3221 machined on it, and the length direction of the straight slotted through hole 3221 is consistent with the length direction of the auxiliary clamping rod 322. The width of the straight slotted through hole 3221 is slightly larger than the diameter of the limiting shaft 325, forming a clearance fit, which allows the limiting shaft 325 to slide freely within the straight slotted through hole 3221, while ensuring the stability of the auxiliary clamping rod 322 when rotating around the limiting shaft 325.

[0085] The extension frame 323 consists of two slender plate-like structures, with the auxiliary clamping rod 322 located between them. The extension frame 323 is fixed to the end of the rotating clamping rod 321 furthest from the rotation axis and extends outward along the length of the rotating clamping rod 321. A limiting shaft 325 is provided at the end of the extension frame 323 furthest from the rotating clamping rod 321. The diameter of the limiting shaft 325 is determined according to the size of the straight slot through hole 3221, ensuring that the limiting shaft 325 does not affect the movement of the auxiliary clamping rod 322, while also serving as a rotational limit within the straight slot through hole 3221.

[0086] Furthermore, the extension frame 323 consists of two elastic plates, typically made of spring steel. The elastic plates are elongated strips, with one end fixed to the end of the rotating clamp 321 away from the axis. The fixing method can be welding or bolting to ensure a secure connection. The elastic plates can elastically deform under stress, moving closer to or further away from the auxiliary clamp 322. The limiting shaft 325 is a screw that passes through the elastic plate along its deformation direction. The two ends of the screw protruding from the elastic plate are threadedly connected to two locking nuts. By rotating the locking nuts, the compressive force on the elastic plate can be adjusted, thereby controlling the degree of elastic deformation.

[0087] The locking piece 324 is a rectangular or circular sheet structure. Several protrusions 3241 are provided on the locking piece 324. The protrusions 3241 are cylindrical or prismatic in shape, and their diameter or side length is determined according to the size of the locking hole 3222 on the auxiliary clamping rod 322. The locking piece 324 is fitted onto the limiting shaft 325 and can slide along the limiting shaft 325. The locking piece 324 can be connected to one end of the elastic pieces that are close to each other via a connecting rod or fixed to the elastic pieces, so that the locking piece 324 can move closer to or away from the auxiliary clamping rod 322 under the action of the elastic pieces. Under the elastic force of the elastic pieces, the locking piece 324 can be pushed closer to the auxiliary clamping rod 322.

[0088] The auxiliary clamping rod 322 has several locking holes 3222 that are adapted to the protrusions 3241 of the locking piece 324. The shape of the locking holes 3222 is consistent with that of the protrusions 3241, and is a cylindrical or prismatic hole. The protrusions 3241 can fully enter the locking holes 3222, effectively restricting the rotation of the auxiliary clamping rod 322. When the balance shaft 01 is installed and it is necessary to fix the auxiliary clamping rod 322 to enhance clamping stability, first slide the auxiliary clamping rod 322 out of the slide groove 3211 and rotate it to the position of pressing the balance shaft 01 cylinder 012. Then, rotate the locking nuts at both ends of the limiting shaft 325 to bring the two locking nuts closer to each other and compress the extension frame 323 (elastic piece). The elastic piece undergoes elastic deformation under the compression of the locking nuts and bends towards the auxiliary clamping rod 322, thereby pushing the locking piece 324 to slide along the limiting shaft 325 closer to the auxiliary clamping rod 322. When the locking piece 324 approaches the auxiliary clamping rod 322, the protrusion 3241 on the locking piece 324 aligns with and enters the locking hole 3222 on the auxiliary clamping rod 322, restricting the rotation of the auxiliary clamping rod 322, ensuring that the auxiliary clamping rod 322 always keeps pressing the shaft cylinder 012 during the rotation of the balance shaft 01, and improving the stability of the clamping assembly 320.

[0089] When it is necessary to disassemble the balance shaft 01, rotate the locking nuts at both ends of the limiting shaft 325 in the opposite direction to move the locking nuts away. The extension bracket 323 (elastic plate) will recover some of its elastic deformation, and the locking plate 324 will move away from the auxiliary clamping rod 322 under the action of elastic force. The protrusion 3241 will disengage from the locking hole 3222, releasing the restriction on the rotation of the auxiliary clamping rod 322. At this time, the auxiliary clamping rod 322 can be slid into the slide groove 3211 to avoid affecting the assembly and disassembly of the balance shaft 01 on the centering fixture 120.

[0090] By cooperating with the protrusion 3241 on the locking piece 324 and the locking hole 3222 of the auxiliary clamping rod 322, the rotation of the auxiliary clamping rod 322 can be precisely restricted. Compared with locking by friction alone, this method is more reliable and further improves the stability of the clamping assembly 320 during the rotation of the balance shaft 01, ensuring the smooth progress of the machining process and improving the machining accuracy.

[0091] Furthermore, to increase the clamping force of the rotating clamping rod 321 and the auxiliary clamping rod 322, a drive assembly for driving the rotating clamping rod 321 to rotate is also included. The drive assembly includes a wedge-shaped pusher 610 and a push rod 620. A groove 3211 or guide rail adapted to the wedge-shaped pusher 610 is machined on the main body 310 of the balance frame 300, so that the wedge-shaped pusher 610 can slide on the main body 310 along a specific direction. The two sides of the wedge-shaped pusher 610 are inclined push surfaces 611, and the two inclined push surfaces 611 correspond to the two rotating clamping rods 321 respectively. During the sliding process of the wedge-shaped pusher 610, the inclined push surfaces 611 can contact the rotating clamping rods 321 and push the rotating clamping rods 321 to rotate around their rotation axis.

[0092] The push rod 620 is fixed to the front end of the wedge-shaped push block 610 by welding, threaded connection or other fastening methods. The end of the push rod 620 near the outer wall of the shaft cylinder 012 can be designed as arc-shaped or spherical to better fit the outer wall of the shaft cylinder 012, increase the contact area, and evenly transmit the pushing force.

[0093] The slope of the inclined push surface 611 can be predicted by the movement of the wedge push block 610, so that the front end of the push rod 620 and the side of the rotating clamp rod 321 can simultaneously contact the axis of the rotary spindle 110. In this way, when machining balance shafts 01 of different diameters, it can still be ensured that the push rod 620 and the rotating clamp rod 321 can simultaneously contact the outer wall of the balance shaft 01 cylinder 012 during the movement of the wedge push block 610.

[0094] The movement of the wedge-shaped pusher 610 synchronously drives the push rod 620 and the two rotating clamping rods 321 to move together. By selecting the slope of the inclined push surface 611, the rotating clamping rods 321 and the push rod 620 can synchronously contact the outer walls of the cylinders 012 with different diameters to achieve clamping. The push rod 620, the two rotating clamping rods 321 and the two auxiliary clamping rods 322 form a five-point clamping structure. Along the axial section of the balance shaft 01, the five clamping points are inscribed in a pentagon, thereby achieving multi-directional clamping and avoiding detachment caused by clamping in one direction.

[0095] To ensure the reset of the rotating clamp 321, a reset torsion spring can be added between the rotating shaft of the rotating clamp 321 and the main body 310. Alternatively, the two ends of the rotating clamp 321 can be located on both sides of the rotating shaft, with the end that does not participate in the clamping action slidingly connected to the inclined push surface 611.

[0096] Furthermore, to avoid directly installing the drive device for rotating the clamping rod 321 on the main body 310, which would reduce the lifespan of the drive device due to centrifugal force, the wedge-shaped pusher 610 has a drive through hole 612 penetrating its body. The inner wall of the drive through hole 612 is machined with a spiral slide 613. The pitch of the spiral slide 613 is generally between 10-30mm, and the helix angle is usually in the range of 15°-45°, so that when the rotating rod 630 rotates, the rotation can be effectively converted into linear sliding of the wedge-shaped pusher 610.

[0097] The drive assembly also includes a rotating rod 630, a rotating drive device 640, and a tightening bolt 650. The rotating rod 630 is rotatably mounted on the main body 310 of the balance frame 300 via bearings, and its position corresponds to and is located within the drive through hole 612 of the wedge-shaped pusher 610. Multiple spiral slides 613 can be configured, and these multiple bolt slides are arranged in a non-intersecting circumferential array along the inner wall of the drive through hole 612.

[0098] A pusher post 631, adapted to the spiral slide 613, is fixed on the outer wall of the rotating rod 630. The pusher post 631 can be connected to the rotating rod 630 by welding or integral molding. The number of pusher posts 631 is determined according to the number of spiral slides 613, generally 2-4, evenly distributed in the circumferential direction of the rotating rod 630. The pusher post 631 is cylindrical in shape, and its diameter matches the width of the spiral slide 613.

[0099] The rotary drive device 640 is slidably mounted on the support frame 200 via a linear guide rail and a slider assembly. The linear guide rail is mounted on the support frame 200 along the direction of approaching or moving away from the rotating rod 630, ensuring that the rotary drive device 640 can smoothly approach or move away from the rotating rod 630. When the rotary drive device 640 slides close to one end of the rotating rod 630, the drive gear meshes with the teeth or grooves at the end of the rotating rod 630, the motor starts and drives the gearbox to rotate, thereby driving the rotating rod 630 to rotate. When the rotating clamping rod 321 reaches a suitable clamping degree, the rotary drive device 640 slides away from the rotating rod 630 to avoid interference between the rotating rod 630 and the rotary drive device 640 during the rotation of the balance shaft 01.

[0100] A threaded hole adapted to the tightening bolt 650 is machined on the main body 310 of the balance frame 300. The tightening bolt 650 is screwed into the threaded hole from the radial direction of the rotating rod 630. The end of the tightening bolt 650 can be flat or spherical. The flat end can better contact the surface of the rotating rod 630 and transmit the tightening force. When the rotating rod 630 rotates to the appropriate position, so that the wedge-shaped push block 610 pushes the rotating clamping rod 321 to the required clamping degree, the tightening bolt 650 is tightened. The end of the tightening bolt 650 presses against the rotating rod 630 to prevent the rotating rod 630 from rotating due to external force, thereby maintaining the position of the wedge-shaped push block 610 and maintaining the clamping state of the rotating clamping rod 321.

[0101] The rotation drive device 640 is mounted on the support frame 200, and the rotation clamping rod 321 is driven to rotate indirectly. This effectively avoids the drive device directly bearing the centrifugal force caused by the rotation of the balance shaft 01, significantly extends the service life of the drive device, reduces equipment maintenance costs, improves the stability and reliability of equipment operation, and ensures the continuity of the processing of the balance shaft 01.

[0102] Through the cooperation of the rotating rod 630 and the spiral slide 613, the rotating drive device 640 can control the sliding distance of the wedge-shaped push block 610, thereby adjusting the clamping degree of the rotating clamping rod 321. The operator can control the clamping force by controlling the rotation angle of the rotating drive device 640 according to the specific conditions of the balance shaft 01, thus improving the stability of clamping and machining accuracy.

[0103] Furthermore, to enhance the overall safety of the device, a trigger switch can be added to the end of the tightening bolt 650. When the trigger switch is activated, it can send a signal to the controller. After the controller receives the signal, the rotary spindle 110 can be started.

[0104] On the other hand, the present invention also provides a method for machining a balance shaft, which uses a balance shaft machining device to machine a balance shaft, characterized by comprising:

[0105] S10, rough machining of shaft head 011, assembly and welding connection of shaft head 011 and shaft cylinder 012, and then welding and assembling shaft bracket 013 onto shaft cylinder 012 to obtain balance shaft 01 blank;

[0106] S20, use a machining device to perform precision machining on the outer diameter of the shaft head 011.

[0107] Furthermore, S20 includes:

[0108] S21, place the balance frame 300 onto the swing support 210;

[0109] S22, assemble the balance shaft 01 blank onto the centering fixture 129, adjust the mass of the balance frame 300 according to the mass of the shaft frame 013, and move the balance frame 300 to a position symmetrical to the shaft frame 013;

[0110] S23, clamp the shaft cylinder 012 using the clamping assembly 320, and then rotate the swing support 210 away from the balance frame 300;

[0111] S24, start the rotary spindle 110 to perform precision machining on the shaft head 011.

[0112] Optionally, the shaft head 011 can be pre-machined using lathes, milling machines, or other machining equipment. This removes most of the excess material from the raw shaft head 011, roughly shaping it to the required form and size, leaving room for subsequent finishing. Then, high-precision machining equipment such as grinding machines is used to finish the mating surfaces of the shaft head 011 and the shaft tube. Through grinding, the surface roughness of the mating surfaces is reduced to a low level, such as Ra0.8-Ra1.6μm, while ensuring dimensional accuracy with tolerances controlled within ±0.01-±0.05mm to guarantee a tight fit between the shaft head 011 and the shaft tube during assembly.

[0113] Assemble the precision-machined shaft end 011 with the shaft tube, ensuring a tight fit between their mating surfaces. Either an interference fit or a clearance fit can be used. If an interference fit is used, the size of the mating surface of the shaft end 011 should be slightly larger than the size of the mounting hole in the shaft tube, with the interference amount generally controlled between 0.02-0.05 mm. Press or install the shaft end 011 into the shaft tube using a press or heat fitting method. Then, employ a suitable welding process, such as argon arc welding or CO2 gas shielded welding, to weld the connection between the shaft end 011 and the shaft tube. During welding, control the welding parameters to ensure a uniform and strong weld, avoiding welding defects such as porosity and cracks.

[0114] Install the shaft bracket 013 onto the shaft cylinder 012, ensuring its position meets the design requirements of the balance shaft 01. The accuracy of the shaft bracket 013's installation position can be ensured by marking the position on the shaft cylinder 012 or using positioning fixtures. Then, employ a suitable welding process to weld the connection between the shaft bracket 013 and the shaft cylinder 012. Welding parameters are adjusted based on the material and thickness of the shaft bracket 013 and the shaft cylinder 012 to guarantee welding quality, ensuring the shaft bracket 013 is securely connected to the shaft cylinder 012, thus obtaining the balance shaft 01 blank.

[0115] Using the counterweight method, based on the structure of the balance shaft 01 blank, including the dimensions and mass distribution of the shaft head 011, shaft tube, and shaft bracket 013, the installation position and required mass of the balance frame 300 are calculated. Through precise mechanical calculations, the side of the shaft tube 012 where the balance frame 300 should be placed, and the mass of the balance frame 300, are determined so that the center of mass of the balance shaft 01 and the balance frame 300 as a whole is located on the axis of the balance shaft 01.

[0116] Install the machining balance shaft 01 with the balance frame 300 installed onto the balance shaft 01 machining device, and perform precision machining on the outer circle of the shaft head 011 to ensure that the rotary spindle 110, centering fixture 120 and other components work normally.

[0117] By first roughing and finishing the assembly surface of the shaft head 011, then assembling and welding the shaft head 011 with the shaft tube and shaft bracket 013, and finally installing the balance bracket 300 and finishing the outer diameter of the shaft head 011, the machining accuracy is controlled step by step. In particular, finishing the outer diameter of the shaft head 011 after installing the balance bracket 300 avoids the impact of multiple welding on the dimensional accuracy of the shaft head 011, effectively improving the overall machining accuracy of the balance shaft 01.

[0118] Furthermore, the aforementioned balance shaft 01 machining device is used to process S40 and S50.

[0119] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A balance shaft machining device, characterized in that, include: The frame (100) is equipped with a rotary spindle (110) and a centering clamp (120). The centering clamp (120) can center and clamp the shaft head (011) of the balance shaft (01) and drive the balance shaft (01) to rotate as a whole. A support frame (200) is provided on one side of the frame (100), and a swing bracket (210) is swayed on the support frame (200). The balance frame (300) includes a main body (310) and a clamping assembly (320). The clamping assembly (320) is used to clamp on the outer periphery of the shaft sleeve (012) of the balance shaft (01) so that the balance frame (300) can rotate with the balance shaft (01). The balance frame (300) and the shaft bracket (013) on the balance shaft (01) are located on both sides of the shaft sleeve (012). The swing support (210) is used to support the balance frame (300). When the clamping assembly (320) clamps the balance shaft (01), the swing support (210) can swing away from the balance frame (300) so that the balance frame (300) rotates with the balance shaft (01). The clamping assembly (320) includes: There are two rotating clamps (321), both of which are rotatably mounted on the main body (310). The two rotating clamps (321) can rotate towards each other to clamp the upper and lower sides of the shaft cylinder (012). An auxiliary clamping rod (322) is rotatably disposed at one end of the rotating clamping rod (321) away from the rotation axis. The auxiliary clamping rod (322) can rotate and extend outward from the rotating clamping rod (321) to cooperate with the rotating clamping rod (321) to clamp the side of the shaft cylinder (012). It also includes a drive assembly for driving the rotation of the rotating clamp (321), the drive assembly comprising: A wedge-shaped pusher (610) is slidably disposed on the main body (310) for approaching or moving away from the shaft cylinder (012). The wedge-shaped pusher (610) has an inclined pushing surface (611) for pushing the rotating clamp (321) to rotate. A push rod (620) is disposed on the wedge-shaped push block (610) and extends between the two rotating clamp rods (321). The push rod (620) can approach the shaft cylinder (012) and abut against the outer wall of the shaft cylinder (012) under the drive of the wedge-shaped push block (610). The wedge-shaped pusher (610) has a drive through hole (612), the inner wall of which has a spiral slide (613), and the drive assembly further includes: A rotating rod (630) is rotatably mounted on the main body (310) and located within the drive through hole (612). The outer wall of the rotating rod (630) has a pusher (631) adapted to the spiral slide (613). The pusher (631) is located within the spiral slide (613) so that the rotation of the rotating rod (630) can drive the wedge-shaped pusher (610) to slide. A rotation drive device (640) is slidably mounted on the support frame (200). The rotation drive device (640) can slide close to one end of the rotating rod (630) and drive the rotating rod (630) to rotate. A tightening bolt (650) is threaded onto the body (310), and the tightening bolt (650) is able to approach the rotating rod (630) radially from the rotating rod (630) and tighten the rotating rod (630).

2. The balance shaft machining device according to claim 1, characterized in that, The main body (310) is provided with a weight adjustment box (400), and a number of mass adjustment blocks are snapped into the weight adjustment box (400) to match the mass of the balance frame (300) and the shaft frame (013).

3. The balance shaft machining device according to claim 1, characterized in that, It also includes a moving component (500) for moving the support frame (200), the moving component (500) comprising: A sliding frame (510) is slidably disposed on one side of the frame (100), and the sliding direction of the sliding frame (510) is parallel to the axial direction of the rotary spindle (110). The lifting frame (520) is lifted and lowered on the sliding frame (510), and the support frame (200) is mounted on the lifting frame (520).

4. The balance shaft machining device according to claim 1, characterized in that, The rotating clamping rod (321) has a groove (3211) at one end away from the rotation axis, and the auxiliary clamping rod (322) can slide into the groove (3211). The auxiliary clamping rod (322) has a straight slot through hole (3221). The clamping assembly (320) also includes: An extension frame (323) is provided at the end of the rotating clamp (321) away from the axis and extends along the length direction of the rotating clamp (321). A limit shaft (325) is provided at the end of the extension frame (323) away from the rotating clamp (321). The limit shaft (325) is located in the straight groove through hole (3221) so that the auxiliary clamp (322) can rotate around the limit shaft (325) after sliding away from the slide groove (3211). A locking piece (324) is slidably disposed on the limiting shaft (325). The locking piece (324) can slide close to the auxiliary clamp (322) and can abut against the side wall of the auxiliary clamp (322) to lock the rotation of the auxiliary clamp (322).

5. A balance shaft machining device according to claim 4, characterized in that, The extension frame (323) is composed of elastic plates. The extension frame (323) can elastically approach the auxiliary clamping rod (322). The limiting shaft (325) is a screw. The limiting shaft (325) passes through the extension frame (323) along the deformation direction of the extension frame (323). The two ends of the limiting shaft (325) that pass through the extension frame (323) are respectively threaded to two locking nuts. The two locking nuts can rotate and compress the extension frame (323) to elastically deform and push the locking plate (324) closer to the auxiliary clamping rod (322). The auxiliary clamping rod (322) has a plurality of locking holes (3222), and the locking piece (324) has a plurality of protrusions (3241) that are adapted to the locking holes (3222). After the locking piece (324) slides close to the auxiliary clamping rod (322), the protrusions (3241) can enter the locking holes (3222) to restrict the rotation of the auxiliary clamping rod (322).

6. A method for machining a balance shaft, comprising machining a balance shaft using a balance shaft machining apparatus according to any one of claims 1 to 5, characterized in that, include: S10, rough machining of the shaft head (011), assembly and welding connection of the shaft head (011) and shaft cylinder (012), and then welding and assembling of the shaft bracket (013) onto the shaft cylinder (012) to obtain the balance shaft (01) blank; S20, use a machining device to perform precision machining on the outer diameter of the shaft head (011).

7. A method for machining a balance shaft according to claim 6, characterized in that, S20 includes: S21, the balance frame (300) is placed on the swing support (210). S22, the balance shaft (01) blank is assembled onto the centering fixture (120), the mass of the balance frame (300) is adjusted according to the mass of the shaft frame (013), and the balance frame (300) is moved to a position symmetrical to the shaft frame (013); S23, clamp the shaft cylinder (012) using the clamping assembly (320), and then rotate the swing support (210) away from the balance frame (300). S24, the rotary spindle (110) is started to perform finishing on the shaft head (011).

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