A constant-clamping-force crankshaft gear hobbing fixture

Abstract

This invention relates to the field of gear hobbing fixtures, specifically a crankshaft gear hobbing fixture with constant clamping force. It includes an operating table that provides a supporting foundation for the entire device. A first assembly table and a second assembly table are stacked sequentially on the operating table, and the three are fastened together by bolts to form a tower-like support structure. A clamping mechanism, located on top of the second assembly table, is used to achieve constant clamping of the crankshaft gear hobbing, ensuring processing stability. An airtightness detection mechanism, located on top of the clamping mechanism, is used to detect the airtightness between the fixture and the gear hobbing, determining whether there are air leakage gaps at the contact point, thereby verifying the reliability of the clamping. This crankshaft gear hobbing fixture with constant clamping force, through the coordinated operation of "gas injection + negative pressure recovery," can accurately detect air leakage gaps at the contact point between the chuck and the gear hobbing.

Description

Technical Field

[0001] This invention relates to the field of gear hobbing fixtures, specifically to a crankshaft gear hobbing fixture with constant clamping force. Background Technology

[0002] As a core transmission component of power equipment such as engines and compressors, the machining accuracy of the hobbing structure of the crankshaft directly determines the transmission efficiency, operational stability, and service life of the equipment. During the cutting and grinding processes of crankshaft hobbing, a clamping mechanism is required to accurately and securely position and fix the hobbing gears to avoid defects such as tooth profile deviation and dimensional out-of-tolerance caused by vibration and displacement during the machining process.

[0003] Currently, most clamping equipment for crankshaft gear hobbing in the industry uses traditional mechanical clamping methods, lacking dedicated sealing detection mechanisms and relying solely on operator experience to determine clamping reliability. While these devices can meet basic clamping requirements, the increasing precision demands of high-end power equipment in gear hobbing have exposed problems such as unstable clamping force, inability to quantify and detect fit sealing, and untimely gap identification. Especially in batch processing scenarios, traditional equipment struggles to guarantee the clamping reliability of each workpiece, easily leading to batch defects. Furthermore, the inability to provide early warnings of clamping defects increases processing risks and costs, necessitating the development of integrated equipment with precise clamping and real-time airtightness detection capabilities. Summary of the Invention

[0004] The present invention provides a crankshaft hobbing fixture with constant clamping force to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a crankshaft hobbing fixture with constant clamping force, comprising an operating table, the operating table providing a support foundation for the entire device; a first assembly table and a second assembly table are stacked sequentially on the operating table, and the three are fastened together by bolts to form a tower-shaped support structure; A clamping mechanism is located on the top of the second assembly table to achieve constant clamping of the crankshaft hobbing and ensure machining stability. An airtightness testing mechanism is located on top of the clamping mechanism to test the airtightness between the clamp and the gear hobbing, determine whether there are any air leakage gaps at the contact points, and thus verify the reliability of the clamping. The clamping mechanism includes a chuck, the outer side of which is interference-fitted with the hobbing gear to achieve initial positioning and clamping of the hobbing gear. The chuck is adapted to the airtightness detection mechanism to form a sealed space. An air vent ring is fixedly connected to the outer side of the chuck. The air vent ring is a hollow ring structure with an opening at the top. An outer connecting ring is fixedly connected to the outer side of the vent ring. The outer connecting ring is fixedly installed on the top of the second assembly table. A sealing ring is fixedly connected to the outer side of the outer connecting ring. The top of the sealing ring is squeezed and fitted to the bottom of the gear to achieve bottom sealing and prevent gas leakage.

[0006] Preferably, the bottom of the second assembly platform is provided with a first air groove, and the bottom of the air outlet ring is provided with a connecting hole, which is connected to the first air groove to form a gas flow channel. A connecting pipe is fixedly installed at the bottom of the No. 2 assembly platform, and the top end of the connecting pipe is connected to the bottom of the No. 1 gas tank for gas transmission.

[0007] Preferably, a pump body is fixedly installed on the inner side of the No. 1 assembly platform through a connecting plate. The top end of the pump body is fixedly connected to the connecting pipe, and the bottom end is connected to an external gas source pipeline to realize gas supply and recovery. The pump body, connecting pipe and No. 1 air tank are all in groups of four, with two forming a group; one group is used to blow air into the contact area between the chuck and the gear, and the other group is used to absorb and recover the ejected gas, forming a gas circulation detection loop.

[0008] Preferably, a frame is fixedly installed on the inner side of the second assembly table, and a hydraulic cylinder is fixedly installed at the center of the frame, with the output end of the hydraulic cylinder extending and retracting in the vertical direction; A sleeve block is fixedly connected to the outer side of the output end of the hydraulic cylinder, which rises and falls synchronously with the hydraulic cylinder; a fitting rod is fixedly connected to the top of the hydraulic cylinder, and a positioning groove is opened on the top of the fitting rod to position the relative position of the airtightness detection mechanism and the clamp, so as to ensure the sealing of the connection between the two.

[0009] Preferably, an internal base is fixedly installed inside the second assembly table, and a hollow rod is fixedly installed at the bottom of the internal base; The top of the hollow rod is provided with an adapter groove, the outer side of which is slidably adapted to the chuck, realizing the sliding guidance and positioning support of the chuck.

[0010] Preferably, the inside of the clamp is provided with a through groove, and a sloping plate is slidably adapted in the through groove. The bottom of the sloping plate is pressed and adapted to the sleeve block, and the sloping plate is slidably adapted to the adaptation groove opened on the top of the hollow rod. A return spring is fixedly connected inside the slot, and a clamping head is fixedly connected to the end of the return spring away from the slot. The outer side of the clamping head is in contact with and sealed to the outer side of the clamp.

[0011] Preferably, the bottom of the clamping head is pressed and adapted to the inclined end on the outer side of the inclined plate to form an inclined transmission structure; During operation, the socket block abuts against the inclined plate and drives it to move up and down along the slot. The inclined plate, through the pressure of the inclined surface, drives the clamping head to extend out from the slot and fit against the inner wall of the hobbing tooth to achieve constant clamping of the hobbing tooth. The top of the clamp is provided with a fitting groove for fitting and positioning with the airtightness testing mechanism.

[0012] Preferably, an annular groove is provided on the outer side of the clamp, a miniature push rod is fixedly installed in the annular groove, a collar is fixedly connected to the outer side of the output end of the miniature push rod, and sliding grooves are provided on both the upper and lower sides of the inner cavity of the collar. A slider is slidably adapted in the sliding groove, and a sticking ring is fixedly connected to the end of the slider away from the sliding groove. Both ends of the sticking ring are fixedly connected to the clamping head. The collar and the abutment are used to compensate for the non-contact areas between the gear and the clamping head, while also enhancing the sealing effect and preventing gas leakage.

[0013] Preferably, the airtightness testing mechanism includes a docking body, and an L-shaped rod is fixedly connected to the outside of the docking body, the L-shaped rod being slidably adapted to the fitting groove; A plug rod is fixedly installed at the center of the bottom of the docking body. The bottom of the plug rod is inserted into and adapted to the groove opened at the top of the fitting rod. The outer side of the plug rod is sealed and adapted to the center of the clamp to prevent gas from escaping from the bottom of the clamp.

[0014] Preferably, an isolation cover is fixedly connected to the outside of the L-shaped rod. The isolation cover is used to guide the gas leaking between the hobbing gear and the chuck to the second gas groove to achieve directional collection of the leaked gas. The bottom of the docking body is provided with a No. 3 gas groove, and a gas alarm is fixedly installed on its top. Leaking gas enters the gas alarm through the No. 2 and No. 3 gas grooves in sequence, triggering an alarm. The alarm signal is used to indicate that the clamping force between the hobbing gear and the chuck has not reached a constant standard, and there is a gap at the contact point between the two.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. A closed gas circulation detection loop is constructed. Through the coordinated operation of "gas injection + negative pressure recovery", the leakage gap at the contact point between the clamp and the gear can be accurately detected. With the double protection of the bottom sealing ring and the compensation sealing structure, the leakage of detection gas is effectively prevented, improving the sensitivity and accuracy of leakage detection and timely identifying potential problems with unreliable clamping.

[0016] 2. The clamping action and the airtightness testing process are seamlessly integrated. The sealing reference positioning is completed at the same time as the clamping mechanism, without the need for additional manual adjustment of the sealing components. The test results are fed back in real time. If the test is qualified, it can directly enter the processing process. If it is unqualified, an alarm will be triggered immediately. This greatly simplifies the connection steps between clamping, testing and processing, and improves work efficiency.

[0017] 3. The system adopts a triple clamping mechanism of "interference initial positioning + inclined plane transmission clamping + spring buffer compensation". The hydraulic cylinder drives the clamping head to extend precisely and fit tightly against the inner wall of the hobbing gear. The elastic reaction force of the return spring can buffer and adjust the clamping force to ensure constant and uniform clamping force, avoid hobbing gear deformation or displacement during processing, and ensure processing accuracy.

[0018] 4. The extension stroke of the clamping head can be adapted to hobbing gears with different inner diameters, and the compensating sealing structure can be adapted to the irregular contact surface of the hobbing gears, improving the adaptability to hobbing gears of various specifications; elastic components such as springs and miniature push rods can achieve self-adjustment, reducing rigid contact damage, and all transmission components can move smoothly without jamming, ensuring long-term stable operation of the equipment and reducing maintenance costs. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the external structure of a crankshaft hobbing fixture with constant clamping force according to the present invention.

[0020] Figure 2 This is a cross-sectional view of the crankshaft hobbing fixture of the present invention.

[0021] Figure 3 This is a cross-sectional view of the connecting tube in the crankshaft hobbing fixture of the present invention.

[0022] Figure 4 This is a cross-sectional view of the clamping mechanism of the present invention.

[0023] Figure 5 This is a cross-sectional view of the clamping head in the clamping mechanism of the present invention.

[0024] Figure 6 This is a schematic diagram of the air outlet ring in the clamping mechanism of the present invention.

[0025] Figure 7 This is a cross-sectional view of the inclined plate in the clamping mechanism of the present invention.

[0026] Figure 8 This is a cross-sectional structural schematic diagram of the airtightness testing mechanism of the present invention.

[0027] Figure 9 This is a cross-sectional schematic diagram of the hollow rod in the clamping mechanism of the present invention.

[0028] Figure 10 This is a cross-sectional view of the clamping head in the clamping mechanism of the present invention.

[0029] Figure 11 This is a cross-sectional view of the clamping ring in the clamping mechanism of the present invention.

[0030] In the picture: 1. Operating table; 2. Assembly table No. 1; 3. Assembly table No. 2; 4. Air tightness testing mechanism; 5. Clamping mechanism; 6. Air tank No. 1; 7. Connecting pipe; 8. Pump body; 9. Frame; 10. Hydraulic cylinder; 11. Sleeve block; 12. Fitting rod; 51. Internal seat; 52. Hollowed-out rod; 53. External connecting ring; 54. Air vent ring; 55. Clamp; 56. Slanted plate; 57. Clamping head; 58. Return spring; 59. Fitting groove; 50. Sealing ring; 501. Collar; 502. Slider; 503. Attaching ring; 505. Miniature push rod; 41. Docking body; 42. L-shaped rod; 43. Isolation cover; 44. Gas tank No. 2; 45. Connecting rod; 46. Gas tank No. 3; 47. Gas alarm. Detailed Implementation

[0031] The present invention will now be further described with reference to the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments. It should be understood that the described embodiments are merely some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0032] Please see Figures 1 to 11 The present invention provides a technical solution: Example 1, such as Figure 1 , Figure 2 , Figure 4 , Figure 5 , Figure 7 , Figure 8 , Figure 9 , Figure 10 and Figure 11 As shown, the operating platform 1 provides a rigid support foundation for the entire device. Assembly platform 2 and assembly platform 3 are stacked sequentially on top of it, and the three are fastened together by through bolts, forming a stable tower-like support structure that provides an installation reference for each functional mechanism. The top of assembly platform 3 integrates a clamping mechanism 5 for constant clamping of the crankshaft gear hobbing. An airtightness detection mechanism 4 is fitted onto the top of the clamping mechanism 5 to detect the airtightness of the contact area between the clamp and the gear hobbing, verifying the reliability of the clamping.

[0033] The core component of the clamping mechanism 5 is the chuck 55. The outer side of the chuck 55 is designed with an interference fit with the gear, which can achieve initial positioning and clamping of the gear. After the chuck 55 is adapted to the airtightness detection mechanism 4, it can form a sealed space. An air outlet ring 54 is fixedly connected to the outer side of the chuck 55. The air outlet ring 54 is a hollow ring structure with an open top. An outer connecting ring 53 is fixedly connected to its outer side. The outer connecting ring 53 is fixedly installed on the top of the second assembly table 3 by bolts. A sealing ring 50 is fixedly sleeved on the outer side of the outer connecting ring 53. The top of the sealing ring 50 can be squeezed and adapted to the bottom of the gear to achieve a seal at the bottom of the gear and prevent the detection gas from escaping.

[0034] The crankshaft gear to be processed is smoothly placed outside the chuck 55 of the clamping mechanism 5. The initial positioning of the gear is achieved by the interference fit between the chuck 55 and the gear. At this time, the bottom of the gear is pressed and adhered to the sealing ring 50 on the outside of the outer connecting ring 53, completing the initial sealing of the bottom of the gear and preventing the subsequent detection gas from escaping from the bottom. At the same time, the miniature push rod 505 in the annular groove on the outside of the chuck 55 is in the initial retracted state, and the sealing ring 503 is stored in the corresponding groove on the outside of the chuck 55 along with the clamping head 57, without affecting the initial positioning of the gear.

[0035] A frame 9 is fixedly installed on the inner side of assembly table 3. A hydraulic cylinder 10 is fixedly installed at the center of the frame 9 by bolts. The output end of the hydraulic cylinder 10 extends and retracts in the vertical direction. A sleeve block 11 is fixedly sleeved on the outer side of the output end of the hydraulic cylinder 10. The sleeve block 11 can rise and fall synchronously with the hydraulic cylinder 10. Its top is pressed and fitted with the bottom of the inclined panel 56 to provide lifting driving force for the inclined panel 56. A fitting rod 12 is fixedly connected to the top of the hydraulic cylinder 10. The top of the fitting rod 12 has a positioning groove for positioning the relative position of the airtightness detection mechanism 4 and the clamp 55 to ensure the sealing of the connection between the two.

[0036] An internal base 51 is fixedly installed inside the assembly table 3. A hollow rod 52 is fixedly connected to the bottom of the internal base 51. The top of the hollow rod 52 has an adapter groove, and its outer side is slidably adapted to the chuck 55, providing precise sliding guidance and positioning support for the vertical displacement of the chuck 55. The inside of the chuck 55 has radially distributed through slots, and a sloping plate 56 is slidably adapted to the through slots. A return spring 58 is also fixedly connected to the through slots. A clamping head 57 is fixedly connected to the end of the return spring 58 away from the inner wall of the through slot. The outer side of the clamping head 57 fits and seals against the outer side of the chuck 55. In the initial state, the clamping head 57 is stored in the through slot. The bottom of the clamping head 57 is an arc-shaped curved surface, which is pressed and adapted to the inclined end of the outer side of the inclined plate 56 to form an inclined transmission structure, which can convert the vertical displacement of the inclined plate 56 into the radial extension and retraction displacement of the clamping head 57.

[0037] The hydraulic cylinder 10 on the inner frame 9 of the second assembly table 3 is activated, and the output end of the hydraulic cylinder 10 is controlled to extend vertically, driving the outer fixed sleeve block 11 to rise synchronously. During the rising process, the sleeve block 11 abuts against the bottom of the inclined plate 56 in the groove of the chuck 55 and continuously applies an upward thrust, driving the inclined plate 56 to slide upward along the groove and the matching groove opened at the top of the hollow rod 52. Since the inclined end of the outer side of the inclined plate 56 is pressed and matched with the arc-shaped curved surface at the bottom of the clamping head 57, the upward sliding of the inclined plate 56 is converted into a lateral pressing force on the clamping head 57, pushing the clamping head 57 to extend radially from the groove until the outer side of the clamping head 57 is tightly pressed and fitted against the inner wall of the hobbing tooth.

[0038] During this process, the return spring 58 inside the slot gradually changes from its initial compressed state to a stretched state. The elastic reaction force it generates can provide real-time buffering compensation for the clamping force of the clamping head 57, avoiding overload of the clamping force due to excessive thrust of the hydraulic cylinder 10, or uneven clamping force due to slight irregularities in the inner wall of the hobbing teeth, thus ensuring a constant clamping force of the clamping head 57 on the hobbing teeth. At the same time, the hollow rod 52 at the bottom of the seat 51 inside the second assembly table 3 slides and adapts to the chuck 55, providing precise guidance and positioning support for slight displacement of the chuck 55 during the clamping process, ensuring clamping stability.

[0039] An annular groove is formed on the outer side of the chuck 55, and a miniature push rod 505 is fixedly installed in the annular groove. The output end of the miniature push rod 505 is arranged radially, and a collar 501 is fixedly connected to its outer side. Sliding grooves are formed on both the upper and lower sides of the inner cavity of the collar 501. A slider 502 is slidably adapted in the sliding groove. A retaining ring 503 is fixedly connected to the end of the slider 502 away from the sliding groove. Both ends of the retaining ring 503 are fixedly connected to the clamping head 57. The retaining ring 503 can be synchronously displaced by driving it through the miniature push rod 505, compensating for the non-contact parts between the hobbing gear and the clamping head 57 and enhancing the sealing effect. A fitting groove 59 is formed on the top of the chuck 55 for matching and positioning with the corresponding structure of the airtightness testing mechanism 4 to ensure the sealing performance of the docking.

[0040] After clamping is completed, the micro push rod 505 in the annular groove on the outside of the chuck 55 is activated, and the output end of the micro push rod 505 is extended, driving the collar 501 to move radially. The collar 501 is adapted to the sliding of the slider 502 through the sliding grooves on the upper and lower sides of the inner cavity, driving the adhesive ring 503 to move synchronously. The adhesive ring 503 is fixedly connected to the clamping head 57, which can accurately cover the non-contact parts between the hobbing gear and the clamping head 57 to achieve gap compensation. At the same time, the outer side of the adhesive ring 503 is tightly fitted with the inner wall of the hobbing gear, further enhancing the sealing effect between the chuck 55 and the hobbing gear, and preventing gas leakage during subsequent airtightness testing.

[0041] The collar 501, the adhesive ring 503, and the clamping head 57 all extend outwards at their front ends, while their main bodies are housed inside the clamp 55. This ensures the tight seal between the collar 501 and the adhesive ring 503 and prevents gas leakage.

[0042] Example 2, as follows Figure 1 , Figure 3 , Figure 4 , Figure 6 , Figure 7 and Figure 8 As shown, a first air trough 6 is opened at the bottom of the second assembly platform 3, and a connecting hole is opened at the bottom of the air outlet ring 54, which is connected to the first air trough 6 to form a gas flow channel. A connecting pipe 7 is fixedly installed at the bottom of the second assembly platform 3, and the top end of the connecting pipe 7 is connected to the bottom of the first air trough 6 for gas transmission. Four pump bodies 8 are fixedly installed on the inner side of the first assembly platform 2 through connecting plates. The top ends of the four pump bodies 8 are fixedly connected to the corresponding connecting pipes 7, and the bottom ends are connected to the external gas source pipeline to realize gas supply and recovery. The four pump bodies 8, the four connecting pipes 7, and the four first air troughs 6 are divided into two groups. One group is used to blow air to the contact part of the chuck 55 and the hobbing gear, and the other group is used to absorb and recover the ejected gas to form a closed gas circulation detection loop.

[0043] The four pumps 8 inside the first assembly platform 2 are activated. The four pumps 8 work in two groups: one group of pumps 8 delivers detection gas to the first gas trough 6 at the bottom of the second assembly platform 3 through the corresponding connecting pipe 7. The gas enters the gas outlet ring 54 through the connecting hole at the bottom of the first gas trough 6 and the gas outlet ring 54, and is then evenly sprayed out to the contact area between the chuck 55 and the gear through the hollow structure at the top of the gas outlet ring 54. The other group of pumps 8 forms a negative pressure adsorption with the first gas trough 6 through the corresponding connecting pipe 7, and recovers the gas that has not leaked from the contact area between the chuck 55 and the gear, forming a closed gas circulation detection loop to ensure efficient use of detection gas and no environmental pollution.

[0044] The airtightness testing mechanism 4 includes a docking body 41, with an L-shaped rod 42 fixedly connected to the outside of the docking body 41. The L-shaped rod 42 is slidably adapted to the fitting groove 59 on the top of the clamp 55 to achieve initial positioning and docking of the airtightness testing mechanism 4 and the clamp 55. A plug-in rod 45 is fixedly installed at the center of the bottom of the docking body 41. The bottom of the plug-in rod 45 is inserted into the groove opened on the top of the fitting rod 12, and the outside of the plug-in rod 45 is sealed to the center of the clamp 55 to prevent gas from leaking out from the center of the clamp 55. An isolation cover 43 is fixedly connected to the outside of the L-shaped rod 42. The isolation cover 43 can guide the gas leaking between the hobbing gear and the chuck 55 to the second gas groove 44 on the outside of the docking body 41 to achieve directional collection of the leaked gas. A third gas groove 46 is opened at the bottom of the docking body 41, which is connected to the second gas groove 44. A gas alarm 47 is fixedly installed on the top of the docking body 41. The leaked gas can enter the gas alarm 47 through the second gas groove 44 and the third gas groove 46 in sequence to trigger the alarm.

[0045] If there is a gap in the clamping fit between the chuck 55 and the gear hobbing teeth, the leaking detection gas will be blocked by the isolation cover 43 on the outside of the L-shaped rod 42 and guided to the second gas groove 44. The leaking gas will then flow along the second gas groove 44 to the third gas groove 46 at the bottom of the docking body 41, and then enter the gas alarm 47 through the third gas groove 46. Once the gas alarm 47 detects the gas, it will immediately trigger an alarm, indicating that the current gear hobbing clamping force has not reached a constant standard and there is a gap in the contact area between the chuck 55 and the gear hobbing teeth. The operator needs to stop the machine and readjust the clamping parameters. Conversely, if the gas alarm 47 does not trigger an alarm, it means that the clamping of the chuck 55 and the gear hobbing teeth is reliable and the sealing is good, and the subsequent processing stage can proceed.

[0046] After the air tightness test is completed, the air tightness testing mechanism 4 is disassembled from the top of the chuck 55 and then subjected to gear hobbing.

[0047] After confirming that the clamping is reliable and the airtightness test is qualified, the operator uses a gear hobbing machine to process the fixed crankshaft by gear hobbing. During the processing, the hydraulic cylinder 10 keeps the output end extended, the sleeve block 11 continuously provides support for the inclined plate 56, and the clamping head 57 maintains a constant clamping force under the elastic action of the return spring 58. The sealing ring 503 and the sealing ring 50 work together to ensure the sealing effect.

[0048] After the gear hobbing is completed, an unlocking and reset operation is performed: First, the pump body 8 is shut off to stop gas supply and recovery; the micro push rod 505 is started in reverse to reset the collar 501 and the contact ring 503, releasing the compensation seal and contact of the contact ring 503 on the gear hobbing. Then, the hydraulic cylinder 10 is started in reverse to control its output end to retract, driving the sleeve block 11 to descend synchronously, and the squeezing force of the sleeve block 11 on the inclined plate 56 disappears; the reset spring 58 releases its elastic potential energy, pulling the clamping head 57 back into the groove of the chuck 55, and at the same time, the clamping head 57 drives the inclined plate 56 to slide down along the groove to reset through the inclined plane transmission, releasing the constant clamping on the gear hobbing.

[0049] The working principle of this invention is as follows: At the beginning of the operation, the crankshaft hobbing gear to be processed is placed outside the chuck 55 of the clamping mechanism 5. The interference fit between the chuck 55 and the hobbing gear is used to achieve initial positioning. At this time, the fitting groove 59 at the top of the chuck 55 provides a positioning reference for the docking of the airtightness detection mechanism 4. At the same time, the sealing ring 50 on the outer side of the outer connecting ring 53 at the top of the second assembly table 3 is pressed and adhered to the bottom of the hobbing gear to complete the initial bottom seal and prevent the subsequent detection gas from leaking out.

[0050] The hydraulic cylinder 10 on the inner frame 9 of the second assembly table 3 is activated. The output end of the hydraulic cylinder 10 extends vertically, driving the sleeve block 11 fixed on its outer side to rise synchronously. During the rise of the sleeve block 11, it abuts against the bottom of the inclined plate 56 in the groove of the chuck 55 and drives the inclined plate 56 to slide upward along the groove. Since the inclined surface on the outer side of the inclined plate 56 and the bottom curved surface of the clamping head 57 are adapted to form an inclined transmission structure, the upward sliding of the inclined plate 56 is converted into a lateral squeezing force on the clamping head 57, pushing the clamping head 57 out of the groove and squeezing it against the inner wall of the hobbing gear. During this process, the return spring 58 in the groove changes from a compressed state to a stretched state. Its elastic reaction force can buffer and compensate for the clamping force of the clamping head 57, ensuring that the clamping force is constant. At the same time, the fitting rod 12 at the top of the hydraulic cylinder 10 is adapted to the positioning groove of the airtightness detection mechanism 4, further ensuring the relative positional accuracy of the chuck 55 and the airtightness detection mechanism 4, and ensuring the sealing after the two are connected.

[0051] After the gear hobbing clamping is completed, the pump body 8, which is fixed to the inside of the No. 1 assembly platform 2 by the connecting plate, is activated. The bottom end of the pump body 8 is connected to the external gas source pipeline to supply gas. The four pump bodies 8 are divided into two groups to work in coordination: one group of pump bodies 8 delivers gas to the No. 1 gas slot 6 at the bottom of the No. 2 assembly platform 3 through the connecting pipe 7. The gas enters the interior of the gas outlet ring 54 through the connecting hole at the bottom of the No. 1 gas slot 6, and then is sprayed out to the contact area between the chuck 55 and the gear hobbing through the hollow structure at the top of the gas outlet ring 54; the other group of pump bodies 8 forms a negative pressure adsorption with the No. 1 gas slot 6 through the corresponding connecting pipe 7, recovering the gas that has not leaked from the contact area, forming a closed gas circulation detection loop. If there is a gap in the clamping fit between the chuck 55 and the gear, the leaked gas will be guided by the isolation cover 43 to the second gas slot 44, and then enter the gas alarm 47 through the third gas slot 46 at the bottom of the docking body 41, triggering an alarm to indicate that the clamping force has not reached the constant standard and there is a gap in the fitting part; conversely, if the gas alarm 47 is not triggered, it indicates that the clamping is reliable and the sealing is good.

[0052] The miniature push rod 505 inside the annular groove on the outer side of the chuck 55 drives the collar 501 to move. The collar 501, through the sliding fit between the sliding groove and the slider 502, drives the padding ring 503 to move synchronously. The padding ring 503 is fixedly connected to the clamping head 57, which can compensate for the non-contact parts between the hobbing gear and the clamping head 57, further preventing the leakage of detection gas. At the same time, the hollow rod 52 fixed at the bottom of the internal seat 51 inside the second assembly table 3 slides and fits with the chuck 55, providing guidance and positioning support for the displacement of the chuck 55, ensuring the stability of the clamping and detection process. After processing, the output end of the hydraulic cylinder 10 retracts, the squeezing force of the sleeve block 11 on the inclined plate 56 disappears, the return spring 58 returns to its original position and pushes the clamping head 57 back into the groove, releasing the clamping of the hobbing gear; the pump body 8 stops working, the airtightness detection mechanism 4 separates from the chuck 55, and the processed hobbing gear can be taken out, completing one work cycle.

[0053] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made by those skilled in the art based on the above concepts without creative effort shall fall within the scope of protection of the present invention.

Claims

1. A crankshaft gear hobbing fixture with constant clamping force, characterized in that, include: The operating platform provides a supporting foundation for the entire device. Assembly platform No. 1 and Assembly Platform No. 2 are stacked on the operating platform in sequence. The operating platform, Assembly Platform No. 1 and Assembly Platform No. 2 are fastened together by bolts to form a tower-shaped support structure. A clamping mechanism is located on the top of the second assembly table to achieve constant clamping of the crankshaft hobbing and ensure machining stability. An airtightness testing mechanism is located on top of the clamping mechanism to test the airtightness between the clamp and the gear hobbing, determine whether there are any air leakage gaps at the contact points, and thus verify the reliability of the clamping. The clamping mechanism includes a chuck, the outer side of which is interference-fitted with the hobbing gear to achieve initial positioning and clamping of the hobbing gear. The chuck is adapted to the airtightness detection mechanism to form a sealed space. An air vent ring is fixedly connected to the outer side of the chuck. The air vent ring is a hollow ring structure with an opening at the top. An outer connecting ring is fixedly connected to the outer side of the vent ring. The outer connecting ring is fixedly installed on the top of the second assembly table. A sealing ring is fixedly connected to the outer side of the outer connecting ring. The top of the sealing ring is squeezed and matched with the bottom of the gear to achieve bottom sealing and prevent gas leakage. The bottom of the No. 2 assembly platform is provided with a No. 1 air groove, and the bottom of the air outlet ring is provided with a connecting hole, which is connected to the No. 1 air groove to form a gas flow channel. A connecting pipe is fixedly installed at the bottom of the No. 2 assembly platform, and the top end of the connecting pipe is connected to the bottom of the No. 1 gas tank for gas transmission. The pump body is fixedly installed on the inner side of the No. 1 assembly platform through connecting plates. The top end of the pump body is fixedly connected to the connecting pipe, and the bottom end is connected to the external gas source pipeline to realize the supply and recovery of gas. The number of pump bodies, connecting pipes and No. 1 air tanks are four in total, and each pair forms a group; one group is used to blow air into the contact area between the chuck and the gear, and the other group is used to absorb and recover the ejected gas to form a gas circulation detection loop. A frame is fixedly installed on the inner side of the No. 2 assembly table, and a hydraulic cylinder is fixedly installed at the center of the frame. The output end of the hydraulic cylinder extends and retracts in the vertical direction. A sleeve block is fixedly connected to the outer side of the output end of the hydraulic cylinder, which rises and falls synchronously with the hydraulic cylinder; a fitting rod is fixedly connected to the top of the hydraulic cylinder, and a positioning groove is opened on the top of the fitting rod to position the relative position of the airtightness detection mechanism and the clamp, so as to ensure the sealing of the connection between the two.

2. The crankshaft hobbing fixture with constant clamping force according to claim 1, characterized in that: An internal base is fixedly installed inside the No. 2 assembly table, and a hollow rod is fixedly installed at the bottom of the internal base; The top of the hollow rod is provided with an adapter groove, the outer side of which is slidably adapted to the chuck, realizing the sliding guidance and positioning support of the chuck.

3. A crankshaft gear hobbing fixture with constant clamping force according to claim 2, characterized in that: The inside of the clamp is provided with a through groove, and a sloping plate is slidably adapted in the through groove. The bottom of the sloping plate is pressed and adapted to the sleeve block, and the sloping plate is slidably adapted to the adaptation groove opened on the top of the hollow rod. A return spring is fixedly connected inside the slot, and a clamping head is fixedly connected to the end of the return spring away from the slot. The outer side of the clamping head is in contact with and sealed to the outer side of the clamp.

4. A crankshaft gear hobbing fixture with constant clamping force according to claim 3, characterized in that: The bottom of the clamping head is pressed and fitted with the inclined end on the outer side of the inclined plate to form an inclined transmission structure; During operation, the socket block abuts against the inclined plate and drives it to move up and down along the slot. The inclined plate, through the pressure of the inclined surface, drives the clamping head to extend out from the slot and fit against the inner wall of the hobbing tooth to achieve constant clamping of the hobbing tooth. The top of the clamp is provided with a fitting groove for fitting and positioning with the airtightness testing mechanism.

5. A crankshaft hobbing fixture with constant clamping force according to claim 3, characterized in that: The outer side of the clamp is provided with an annular groove, and a miniature push rod is fixedly installed in the annular groove. A collar is fixedly connected to the outer side of the output end of the miniature push rod. Sliding grooves are provided on both the upper and lower sides of the inner cavity of the collar. A slider is slidably adapted in the sliding groove. A sticking ring is fixedly connected to the end of the slider away from the sliding groove. Both ends of the sticking ring are fixedly connected to the clamping head. The collar and the abutment are used to compensate for the non-contact areas between the gear and the clamping head, while also enhancing the sealing effect and preventing gas leakage.

6. A crankshaft gear hobbing fixture with constant clamping force according to claim 4, characterized in that: The airtightness testing mechanism includes a docking body, and an L-shaped rod is fixedly connected to the outside of the docking body. The L-shaped rod is slidably adapted to the fitting groove. A plug rod is fixedly installed at the center of the bottom of the docking body. The bottom of the plug rod is inserted into and adapted to the groove opened at the top of the fitting rod. The outer side of the plug rod is sealed and adapted to the center of the clamp to prevent gas from escaping from the bottom of the clamp.

7. A crankshaft gear hobbing fixture with constant clamping force according to claim 6, characterized in that: An isolation cover is fixedly connected to the outside of the L-shaped rod. The isolation cover is used to guide the gas leaking between the hobbing gear and the chuck to the No. 2 gas groove to achieve directional collection of the leaked gas. The bottom of the docking body is provided with a No. 3 gas groove, and a gas alarm is fixedly installed on its top. Leaking gas enters the gas alarm through the No. 2 and No. 3 gas grooves in sequence, triggering an alarm. The alarm signal is used to indicate that the clamping force between the hobbing gear and the chuck has not reached a constant standard, and there is a gap at the contact point between the two.

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