Special tool for turning crankshaft

Abstract

The invention relates to the technical field of clamps, and discloses a crankshaft turning special tool which comprises a chuck base, the chuck base comprises a mounting face and a working face, a counterweight assembly, a movable clamping assembly and a fixing piece are arranged on the working face of the chuck base, and the counterweight assembly and the fixing piece are detachably arranged on the chuck base. The movable clamping assembly comprises two movable clamping blocks which are symmetrically arranged, the two movable clamping blocks are movably arranged on the chuck base, the movable clamping blocks are driven by a driving assembly in the chuck base, and the fixing piece comprises a fixing block and a fixed clamping block installed on the fixing block. According to the eccentric clamping device, eccentric clamping of the crankshaft can be rapidly achieved with high precision.

Description

Technical Field

[0001] The present invention relates to the technical field of fixtures, and in particular to a special tool for crankshaft turning. Background Art

[0002] As a core transmission component in the general machinery field, the general-purpose crankshaft has one or two crank throws. During the turning process, due to the crankshaft's irregular shape, weak rigidity, and eccentric crank throw, direct clamping with a general-purpose lathe fixture can easily lead to unstable clamping, large machining vibrations, and excessive geometric and positional accuracy. Furthermore, machining eccentric areas is difficult. Therefore, crankshaft turning must rely on specialized clamping fixtures to ensure the crankshaft's rotational accuracy and machining stability during turning, and to meet the tolerance requirements for key dimensions such as coaxiality, cylindricity, and eccentricity of the crankshaft's journals.

[0003] Currently, general-purpose crankshaft turning fixtures only have basic clamping capabilities and are not directly adaptable to eccentric turning. Adjusting the eccentricity requires completely loosening the clamping assembly and adjusting the positions of multiple clamping blocks to shift the crankshaft's rotational center. A crankshaft turning fixture, published as CN102581648A, first clamps the crankshaft's journal with a three-jaw chuck. Then, by individually adjusting the four jaws of a four-jaw chuck, the centerline of the crankshaft to be machined is aligned with the rotational centerline of the four-jaw chuck, achieving eccentric clamping of the crankshaft.

[0004] The above invention realizes clamping by a three-jaw chuck and realizes eccentricity adjustment by a four-jaw chuck, but the four jaws of the four-jaw chuck need to be adjusted individually, and manual measurement and repeated correction are required during the adjustment process. In addition, each adjustment requires moving the four jaws for repositioning and calibration, which is inefficient and cannot guarantee processing accuracy. Summary of the Invention

[0005] The present invention aims to provide a special tool for crankshaft turning, which can realize eccentric clamping of the crankshaft quickly and with high precision.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A special tool for crankshaft turning, comprising a chuck base, the chuck base comprising a mounting surface and a working surface, the working surface of the chuck base being provided with a counterweight assembly, a movable clamping assembly and a fixed piece, the movable clamping assembly being located between the fixed piece and the counterweight assembly; the counterweight assembly and the fixed piece being detachably arranged on the chuck base, the movable clamping assembly comprising two symmetrically arranged movable clamping blocks, the two groups of movable clamping blocks being movably arranged on the chuck base, the movable clamping block being driven by a driving assembly inside the chuck base, the fixed piece comprising a fixed block and a fixed clamping block detachably mounted on the fixed block, a clamping area for clamping shaft parts being formed between the fixed clamping block and the movable clamping block, and the clamping area being eccentric to the chuck base.

[0008] The principles and advantages of this solution are:

[0009] 1. There are two radially movable clamping blocks and one fixed clamping block. First, fix the crankshaft journal on the fixed clamping block, and then drive the two movable clamping blocks to retract inward. Through the coordinated action of the three clamping blocks, the crankshaft journal can be accurately clamped, so that the rotation center line of the crank to be processed coincides with the rotation center line of the lathe spindle, realizing eccentric clamping of the crankshaft.

[0010] 2. A clamping area for holding shaft parts is formed between the fixed and movable clamping blocks. This area is eccentric to the chuck base, allowing the clamping force of the clamping blocks to be evenly distributed on the outer circumference of the crankshaft journal, resulting in more balanced force and more secure clamping. The fixed clamping block first eccentrically positions the crankshaft, and then drives the two movable clamping blocks to move and clamp the crankshaft. Manual positioning and adjustment are not required, ensuring high-precision and rapid clamping.

[0011] 3. The counterweight assembly adopts a symmetrical setting and detachable design. The counterweight blocks of different shapes and weights can be flexibly selected and replaced according to the model, weight and eccentricity of the crankshaft to be processed, effectively balancing the rotating centrifugal force, ensuring the dynamic balance of the rotation during lathe processing, and adapting to the processing of crankshafts of different specifications.

[0012] 4. The fixed clamping block can be detachably installed. The most suitable fixed clamping block can be selected for installation according to the eccentricity of the crankshaft throw to meet the needs of different eccentricities.

[0013] In summary, this technology rationally places the fixed parts and counterweight components on either side of the movable clamping assembly. An eccentric clamping area for clamping shaft parts is formed between the fixed and movable clamping blocks. Driving the two sets of movable clamping blocks directly achieves automatic eccentric clamping of shaft parts. Compared to traditional, complex tooling that requires manual adjustment, this technology improves clamping efficiency while ensuring clamping accuracy. Furthermore, the counterweight assembly balances the gravity of the entire tooling, further ensuring machining accuracy.

[0014] Preferably, as an improvement, a chuck mounting piece is provided on the mounting surface of the chuck base for connecting the chuck to the lathe spindle; a strip groove is axially provided on the chuck base passing through the mounting surface and the working surface, and an oil filling hole is provided on the side wall of the chuck base.

[0015] Technical effect: This solution adopts the above-mentioned setting, which makes it easy for the chuck base to be accurately installed on the lathe. The strip groove has a positioning effect, ensuring that the rotation center line of the chuck base and the lathe axle coincides; the oil filling hole is used to add lubricating grease to the inside of the chuck, reducing the friction coefficient between components and extending the service life of the chuck drive mechanism and the entire tooling.

[0016] Preferably, as an improvement, the counterweight assembly includes two symmetrically arranged counterweight blocks, and the counterweight blocks are detachably fixed on the chuck base.

[0017] Technical effect: This solution adopts the above-mentioned setting, which facilitates the disassembly and installation of the counterweight block, and thus facilitates the selection of counterweight blocks of different shapes or weights for counterweighting according to the crankshaft specifications.

[0018] Preferably, as an improvement, the movable clamping block includes a mounting block and a clamping head fixed to one end of the mounting block near the strip groove, the mounting block is detachably mounted on the chuck base, the clamping head is fixed to one end of the mounting block near the center of the chuck base, and the clamping head is tilted downward toward the direction of the fixing member.

[0019] Technical effect: This solution adopts the above-mentioned setting, and the two clamping heads are deflected toward the direction of the fixed clamping block, so that there is a 120° angle (or approximately 120°) between the two mounting blocks and the clamping head, which ensures the tightening effect as much as possible, and the clamping force can be evenly distributed on the outer circumference of the crankshaft journal.

[0020] Preferably, as an improvement, the clamping end of the clamping head is provided with an arc-shaped clamping surface, and the clamping end of the fixed clamping block is provided with an arc-shaped positioning surface.

[0021] Technical effect: This solution adopts the above-mentioned setting, which can increase the contact area between the clamping head and the outer surface of the crankshaft journal and improve the clamping stability.

[0022] Preferably, as an improvement, the mounting block includes a moving block and a clamping block which are arranged overlapping each other, the moving block is movably arranged on the chuck base, the clamping block is detachably fixed on the moving block, and the clamping head is fixed on the clamping block.

[0023] Technical effect: This solution adopts the above-mentioned setting, which makes it easy to replace the clamping block. The appropriate clamping block can be replaced according to the model of different crankshafts, thereby improving the stability of clamping.

[0024] Preferably, as an improvement, the fixing part includes a fixing block and a fixed clamping block installed on the fixing block, the fixing block is detachably arranged on the chuck base, the end face of the fixing block close to the clamping head is provided with a mounting groove, the fixed clamping block covers the outside of the mounting groove, and the side end of the fixed clamping block is detachably connected to the fixed block; the arc-shaped positioning surface is located on the side of the fixed clamping block close to the clamping head.

[0025] Technical effect: This scheme adopts the above-mentioned setting, and the mounting groove not only facilitates the detachable installation of the fixed clamping block, but also can avoid the crankshaft when clamping the crankshaft to avoid interference; and the fixed clamping block is fixed by the mounting platforms on both sides of the mounting groove. Compared with using bolts to directly install the fixed clamping block on the plane, this method reduces the contact area of ​​the plane, reduces the influence of the plane flatness on the installation of the fixed clamping block, and avoids the fixed clamping block from easily rubbing against the plane during installation, causing surface wear and affecting the accuracy.

[0026] Preferably, as an improvement, a through-hole avoidance groove is provided at the bottom of the fixing block.

[0027] Technical effect: This solution adopts the above-mentioned setting, which effectively reduces the overall weight of the fixed block, facilitates the counterweight operation of the counterweight block, and avoids interference with the crankshaft and the fixed block during the clamping process, ensuring smooth clamping without damaging the workpiece.

[0028] Preferably, as an improvement, the mounting groove extends in a square shape along the axis of the chuck base and communicates with the air-avoiding groove.

[0029] Technical effect: This solution adopts the above-mentioned setting, which is convenient for increasing the contact area between the fixed clamping block and the outer surface of the crankshaft journal, thereby improving the clamping stability.

[0030] Preferably, as an improvement, a cleaning assembly is provided on the outside of the chuck base, the cleaning assembly includes a swivel and an annular air cavity located on the swivel, and the swivel rotating seal is sleeved on the chuck base; a gas flow channel connected to the annular air cavity is provided in the chuck base, and the gas outlet end of the gas flow channel is aligned with the arc-shaped clamping surface and / or the arc-shaped positioning surface.

[0031] Technical effect: This solution adopts the above-mentioned setting. The gas blown out of the gas flow channel can clean the arc-shaped clamping surface and the arc-shaped positioning surface, and can blow away the iron filings on the surface, thereby avoiding damage to the crankshaft surface caused by iron filings when clamping the crankshaft, or affecting the clamping accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Schematic diagram of the structure of an embodiment of the present invention.

[0033] Figure 2 It is a side view of an embodiment of the present invention.

[0034] Figure 3 It is a front view of an embodiment of the present invention.

[0035] Figure 4 This is a structural diagram of Example 2 of the present invention.

[0036] Figure 5 This is a structural diagram of Example 3 of the present invention.

[0037] The figure marks in the drawings of the specification include: chuck base 1, chuck mounting part 11, oil filling hole 12, strip groove 13, counterweight block 2, movable clamping block 3, mounting block 31, clamping head 32, arc-shaped clamping surface 33, moving block 34, clamping block 35, fixed block 4, mounting groove 41, air avoidance groove 42, fixed clamping block 5, arc-shaped positioning surface 51, annular air cavity 6, buckle 61, gas flow channel 7, positioning groove 71, blowing air channel 8, positioning nozzle 81, diverter channel 82, clamping area 9, swivel seat 10, swivel 101. DETAILED DESCRIPTION

[0038] Example 1

[0039] This solution provides a special tooling for crankshaft turning, which is basically as shown in the attached Figure 1-3 As shown:

[0040] A tooling for crankshaft machining includes a chuck base 1, which includes a mounting surface and a working surface. In this embodiment, the side where the chuck base 1 is fixed to the lathe spindle is called the mounting surface of the chuck base 1, and the corresponding side is called the working surface of the chuck base 1. Figure 3 As shown, the working surface of the chuck base 1 is provided with a counterweight assembly, a movable clamping assembly and a fixing member from top to bottom. Specifically, Figure 1 As described, the counterweight assembly and the fixing part are detachably arranged on the chuck base 1, the movable clamping assembly includes two symmetrically arranged movable clamping blocks 3, the two movable clamping blocks 3 are movably arranged on the chuck base 1, the two movable clamping blocks 3 can be simultaneously retracted toward the center of the chuck base 1 or simultaneously separated outward, the movable clamping block 3 is driven by the driving assembly inside the chuck base 1, the fixing part includes a fixed block 4 and a fixed clamping block 5 installed on the fixed block 4, the two movable clamping blocks 3 and one fixed clamping block 5 work together to clamp and fix the crankshaft journal.

[0041] The drive assembly (not shown) for the two movable clamping blocks 3 is identical to that of existing two-jaw hydraulic chucks and will not be elaborated on here. The driving principle is that hydraulic oil, flowing through a hydraulic cylinder, pushes a piston, which in turn drives the movable clamping blocks 3, which engage wedge-shaped blocks with wedge-shaped grooves in the chuck body. This converts the piston's axial motion into radial motion, thereby clamping or releasing the crankshaft. Specifically, when clamping the crankshaft, hydraulic oil enters the hydraulic cylinder, pushing the piston and movable clamping blocks 3 toward the center of the chuck. When releasing the workpiece, the hydraulic oil returns, and the movable clamping blocks 3 return to their original position under the action of a spring or other reset mechanism.

[0042] The mounting surface of the chuck base 1 is provided with a chuck mounting member 11 for connecting the chuck to the lathe spindle. The specific mounting method may be through-bolting or fixing. The chuck base 1 is provided with a strip groove 13 axially extending through the mounting surface and the working surface. The strip groove 13 mates with the lathe spindle and achieves a positioning effect when the chuck base 1 is installed. The side wall of the chuck base 1 is provided with an oiling hole 12 for adding lubricating grease to the chuck, which can reduce the friction coefficient between the components and extend the service life of the chuck.

[0043] The counterweight assembly includes two symmetrically arranged counterweight blocks 2, which are detachably fixed to the chuck base 1 by bolts. The counterweight blocks 2 have various shapes and weights and can be replaced according to the model of the crankshaft to be processed to ensure rotational balance during lathe processing.

[0044] The movable clamping block 3 includes a mounting block 31 and a clamping head 32. The mounting block 31 is movably mounted on the chuck base 1 by bolts. The clamping head 32 is set at one end of the two mounting blocks 31 close to each other, and the clamping head 32 is tilted downward toward the direction of the fixed clamping block 5. The clamping end of the clamping head 32 is provided with an arc-shaped clamping surface 33, which contacts the outer surface of the crankshaft journal, thereby increasing the contact area between the clamping head 32 and the crankshaft journal and improving the clamping stability.

[0045] The fixing member includes a fixing block 4 and a fixing clamping block 5 mounted on the fixing block 4. The fixing block 4 is fixed to the chuck base 1 by bolts. A mounting groove 41 is provided on the fixing block 4. A protruding mounting platform (not shown in the figure) is provided near the outer end of the mounting groove 41. Figure 1 As shown, the fixed clamping block 5 covers the mounting groove 41, and the upper and lower ends of the fixed clamping block 5 are detachably connected to the mounting platform by bolts, thereby realizing the installation of the clamping block 5 on the fixed block 4. In this embodiment, the side of the fixed clamping block 5 close to the movable clamping block 3 is called the clamping end of the fixed clamping block 5. The clamping end of the fixed clamping block 5 is provided with an arc-shaped positioning surface 51, which contacts the outer surface of the crankshaft journal, increases the contact area with the crankshaft journal, and improves the clamping stability. Figure 1As shown, the bottom of the fixed block 4 is provided with a through-avoidance groove 42, which is designed to reduce weight, and the avoidance groove 42 can avoid interference between the fixed block 4 and the crankshaft during clamping, which is convenient for clamping the crankshaft; the installation groove 41 extends in a square shape along the axis of the chuck base 1 and is connected to the avoidance groove 42, and the top of the installation groove 41 is stepped, which is convenient for installing the fixed clamping block 5. This technology utilizes the design of the installation groove 41 and the avoidance groove 42, which not only reduces the weight of the fixed block 4, but also reduces the installation error of the fixed clamping block 5 and is convenient for the installation and disassembly of the fixed clamping block 5, and can also achieve avoidance of workpiece clamping. In other embodiments other than this embodiment, a strip groove is provided at the bottom of the arc-shaped positioning surface 51 along the central axis direction. Since debris is easily retained at the bottom, the groove can reduce the contact between the bottom of the shaft parts and the bottom of the strip groove, further improving the product precision and quality.

[0046] Preferably, the two arc-shaped clamping surfaces 33 and the one arc-shaped positioning surface 51 are in contact with the outer surface of the crankshaft journal, and a clamping area 9 for clamping shaft parts is formed between the two arc-shaped clamping surfaces 33 and the arc-shaped positioning surface 51, and the clamping area 9 is eccentrically arranged at the center of the chuck base. Figure 3 As shown, the center of the clamping area 9 is located on the central straight line of the chuck base 1. Two arcuate clamping surfaces 33 are symmetrically arranged along the center line of the clamping area 9, ensuring uniform clamping force on the outer surface of the crankshaft journal. The angle between the mounting block 31 and the clamping head 32 is 120° (or approximately 120°), which facilitates the clamping block's application of force to the outer circumference of the crankshaft journal, ensuring a more balanced force and ensuring effective clamping and fixing.

[0047] When this solution is actually used, the chuck base 1 is first installed on the axle of the lathe. According to the eccentricity of the crank of the crankshaft to be processed, a suitable fixed clamping block 5 is selected, and the selected fixed clamping block 5 is fixed in the installation groove 41 on the fixed block 4 with bolts. Then, a counterweight block 2 of suitable shape and weight is selected, and the counterweight block 2 is fixed to the chuck base 1 with bolts. When clamping the crankshaft, the shaft handles at both ends of the crankshaft are first placed on the arc-shaped positioning surfaces 51 of the fixed clamping blocks 5 at both ends of the lathe, and then the driving assembly in the chuck is started, so that the two movable clamping blocks 3 are retracted toward the middle to clamp the crank of the crankshaft. After clamping is completed, the lathe is started, and the main shaft of the lathe drives the chuck to rotate, thereby driving the crankshaft to rotate. At this time, the rotation centerline of the crank to be processed coincides with the rotation centerline of the main shaft of the lathe, realizing the eccentric clamping of the crankshaft, and then the cutting tool is fed to process the crank.

[0048] Example 2

[0049] As attached Figure 4As shown, this embodiment is different from embodiment 1 in that the movable clamping block 3 includes a moving block 34 and a clamping block 35 that are overlapped in an upper and lower manner. The moving block 34 is movably set on the chuck base 1, and the clamping block 35 is detachably fixed to the moving block 34 by bolts. The moving block 34 is driven by a driving assembly in the chuck, and the clamping block 35 is fixed to the moving block 34 and can move with the moving block 34 to achieve clamping of the crankshaft journal. This technology can facilitate the replacement of the clamping block 35 and ensure the accuracy of clamping. The clamping block 35 includes a mounting block 31 and a clamping head 32. The clamping head 32 is integrally formed at one end of the mounting block 31 near the fixed clamping block 5.

[0050] Example 3

[0051] As attached Figure 5 As shown, this embodiment differs from Embodiments 1 and 2 in that a cleaning assembly is provided on the outside of the chuck base 1. The cleaning assembly includes a swivel seat 10, a swivel 101, and an annular air cavity 6 located on the swivel 101. The swivel 101 is rotatably sealed against the swivel seat 10. The bottom of the swivel 101 extends outward to form a buckle 61, which facilitates rotational engagement within the groove of the swivel seat 10. An annular sealing ring is provided at the buckle. A gas flow channel 7 is provided within the chuck base 1, communicating with the annular air cavity 6. An air inlet pipe connected to the annular air cavity 6 is fixed to the outer wall of the annular air cavity 6. In other embodiments other than this embodiment, the swivel 101 can be fixed to the frame.

[0052] Blowing channels 8 are provided in the fixing blocks 4 on both sides of the air-avoiding groove 42. The upper ends of the blowing channels 8 are used to blow air toward the arc-shaped clamping surface 33, respectively. The lower ends of the blowing channels 8 are provided with positioning nozzles 81. The chuck base 1 is provided with a positioning groove 71 for facilitating the insertion of the positioning nozzles 81. A rubber layer is provided on the groove wall of the positioning groove 71 to facilitate the insertion of the positioning nozzles 81 to achieve a tensioning connection. The positioning nozzles 81 can also facilitate initial positioning when installing the fixing block 4. The blowing channel 8 is provided with a diverter channel 82. The blowing end of the diverter channel 82 can be located on the groove wall of the installation groove 41, aligned with the arc-shaped positioning surface 51.

[0053] During use, the chuck base 1 can rotate freely, and the gas in the rotating ring 101 can clean the arc-shaped clamping surface 33 and the arc-shaped positioning surface 51 through the gas flow channel 7, the blowing flow channel 8, and the branch channel 82, thereby avoiding the influence of debris on product clamping and the influence on product quality.

[0054] The above is only an embodiment of the present invention, and the common knowledge such as the specific technical solutions and / or characteristics in the solution are not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the present invention, several variations and improvements can be made, which should also be regarded as the scope of protection of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the description can be used to interpret the content of the claims.

Claims

1. A tool for crankshaft turning, characterized by: It includes a chuck base, which includes a mounting surface and a working surface. A counterweight assembly, a movable clamping assembly and a fixed piece are provided on the working surface of the chuck base, and the movable clamping assembly is located between the fixed piece and the counterweight assembly; the counterweight assembly and the fixed piece are detachably arranged on the chuck base, and the movable clamping assembly includes two symmetrically arranged movable clamping blocks, and the two groups of movable clamping blocks are movably arranged on the chuck base, and the movable clamping block is driven by a driving assembly inside the chuck base, and the fixed piece includes a fixed block and a fixed clamping block detachably mounted on the fixed block, and a clamping area for clamping shaft parts is formed between the fixed clamping block and the movable clamping block, and the clamping area is eccentric to the chuck base.

2. The special tool for crankshaft turning according to claim 1, characterized in that: A chuck mounting piece is provided on the mounting surface of the chuck base for connecting the chuck to the lathe spindle; a strip groove is axially provided on the chuck base running through the mounting surface and the working surface, and an oil filling hole is provided on the side wall of the chuck base.

3. The tooling for crankshaft turning according to claim 1, characterized in that: The counterweight assembly includes two symmetrically arranged counterweight blocks, and the counterweight blocks are detachably fixed on the chuck base.

4. The tooling for crankshaft turning according to claim 1, characterized in that: The movable clamping block includes a mounting block and a clamping head fixed at one end of the mounting block near the strip groove. The mounting block is detachably mounted on the chuck base. The clamping head is fixed at one end of the mounting block near the center of the chuck base. The clamping head is tilted downward toward the direction of the fixing member.

5. The special tool for crankshaft turning according to claim 4, characterized in that: The clamping end of the clamping head is provided with an arc-shaped clamping surface, and the clamping end of the fixed clamping block is provided with an arc-shaped positioning surface.

6. The tooling for crankshaft turning according to claim 4, characterized in that: The mounting block comprises a moving block and a clamping block which are arranged in an overlapping manner. The moving block is movably arranged on the chuck base. The clamping block is detachably fixed on the moving block. The clamping head is fixed on the clamping block.

7. The tooling for crankshaft turning according to claim 1, characterized in that: The fixing part includes a fixing block and a fixed clamping block installed on the fixing block. The fixing block is detachably arranged on the chuck base. The end face of the fixing block close to the clamping head is provided with a mounting groove. The fixed clamping block covers the outside of the mounting groove, and the side end of the fixed clamping block is detachably connected to the fixed block; the arc-shaped positioning surface is located on the side of the fixed clamping block close to the clamping head.

8. The special tool for crankshaft turning according to claim 7, characterized in that: A through-hole avoidance groove is provided at the bottom of the fixing block.

9. The tooling for crankshaft turning according to claim 7, characterized in that: The mounting groove extends in a square shape along the axis of the chuck base and is communicated with the air-avoiding groove.

10. The special tool for crankshaft turning according to claim 9, characterized in that: A cleaning assembly is provided on the outside of the chuck base, and the cleaning assembly includes a rotating ring and an annular air cavity located on the rotating ring, and the rotating ring is rotated and sealed on the chuck base; a gas flow channel connected to the annular air cavity is provided in the chuck base, and the gas outlet end of the gas flow channel is aligned with the arc-shaped clamping surface and / or the arc-shaped positioning surface.

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