Thin-wall valve seat machining clamp

Abstract

The utility model provides a thin-wall valve seat machining clamp, which belongs to the technical field of precision machinery manufacturing, and comprises a fixing part and a clamping part, the clamping part is detachably connected with the fixing part, the fixing part comprises a core shaft part and a convex part, the surface of the core shaft part is provided with a plurality of groups of positioning holes, the clamping part is connected with the clamping part through a positioning pin, and the convex part is provided with a plurality of groups of positioning holes. The clamping part comprises a positioning disc, a through hole used for fixing a positioning pin is formed in the positioning disc, the clamping part further comprises a pressing plate, one side of the positioning disc is in contact with the mandrel part, the other side of the positioning disc is in contact with the pressing plate, one side of the pressing plate is in contact with the positioning disc, the other side of the pressing plate is in contact with a nut, and the clamping part is fixedly connected with the threads on the protruding part in a matched mode through the nut; a threaded hole is formed in the surface of the mandrel; the positioning disc is fixedly connected with the mandrel through a bolt corresponding to the threaded hole; mounting holes matched with the lug bosses in size are formed in the centers of the positioning disc and the pressing plate; according to the utility model, the problem of deformation caused by radial deviation easily generated by plane positioning can be solved.

Description

Technical Field

[0001] This utility model belongs to the field of precision machinery manufacturing technology, and specifically relates to a clamping device for machining thin-walled valve seats. Background Technology

[0002] In the field of precision machinery manufacturing, valve seats are common mechanical components, and valve seat clamping fixtures are widely used in the manufacture of various valves. Thin-walled valve seats typically consist of thin-walled profiles, which possess high strength and corrosion resistance. However, due to their thin walls and poor rigidity, they are prone to deformation during processing, affecting machining accuracy and quality. Therefore, how to ensure machining accuracy while avoiding deformation of thin-walled valve seats has become an urgent problem to be solved during the machining process.

[0003] In the machining of thin-walled valve seats, traditional clamping methods often fail to fully consider the characteristics of the thin-walled structure, leading to workpiece deformation during machining and affecting machining accuracy and quality. Existing clamping devices often suffer from uneven clamping force, easy workpiece deformation, and inaccurate positioning, severely impacting the machining efficiency and quality of thin-walled valve seats.

[0004] Therefore, considering the above, the current thin-walled valve seat machining fixtures have the problem that radial offset can easily occur due to planar positioning, leading to deformation. Utility Model Content

[0005] In view of this, the present invention provides a machining and clamping method for thin-walled valve seats, which can solve the problem of radial offset and deformation caused by planar positioning.

[0006] This utility model is implemented as follows:

[0007] This utility model provides a clamping device for machining thin-walled valve seats, comprising a fixing part and a clamping part, which are detachably connected. The fixing part includes a spindle part and a protrusion part. The surface of the spindle part is provided with multiple sets of positioning holes. The clamping part is connected to the clamping part by positioning pins. The clamping part includes a positioning plate with through holes for fixing the positioning pins. The clamping part also includes a pressure plate. One side of the positioning plate contacts the spindle part, and the other side contacts the pressure plate. One side of the pressure plate contacts the positioning plate, and the other side contacts a nut. The clamping part is fixedly connected by the nut and the threaded engagement on the protrusion part.

[0008] Based on the above technical solution, the thin-walled valve seat machining and clamping method of this utility model can be further improved as follows:

[0009] The mandrel surface is also provided with threaded holes, and the positioning plate is fixedly connected to the mandrel by bolts corresponding to the threaded holes.

[0010] Furthermore, both the positioning plate and the pressure plate have mounting holes at their centers that are adapted to the size of the protrusion.

[0011] Furthermore, a recessed platform is provided on the outer edge of the positioning disk.

[0012] Furthermore, the outer diameter of the pressure plate is matched with the inner diameter of the recess.

[0013] The beneficial effects of adopting the above-mentioned improved scheme are as follows: through the cooperation of the pressure plate and the positioning plate, the clamping force can be evenly applied to all positions of the thin-walled valve seat, avoiding the uneven clamping force that occurs in the traditional clamping method, thereby reducing the risk of deformation.

[0014] Furthermore, the outer side of the recessed platform is provided with 6-8 independent petal-shaped elastic claws. Each elastic claw is connected to the central disk through a circumferentially distributed arc-shaped groove. The groove is 2-3mm wide and 2 / 3 the thickness of the pressure plate.

[0015] Furthermore, the locating pin is a tapered locating pin, which is interference-fitted with the locating hole.

[0016] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: by using multiple sets of positioning holes and positioning pins, and through interference fit and threaded connection, high-precision positioning is achieved, ensuring the stability and high precision of the thin-walled valve seat during the processing.

[0017] Furthermore, the outer ring of the pressure plate is a wavy curved surface with alternating peaks and troughs, a wave height of 0.3-0.5mm, and a wavelength of 5-8mm.

[0018] The beneficial effects of adopting the above-mentioned improved scheme are as follows: the clamping force is effectively dispersed by the corrugated pressure plate and the elastic claw structure, and the deformation of the thin-walled valve seat during the processing is effectively avoided by the adaptation and buffering effect of the elastic claw. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments of this utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A cross-sectional schematic diagram of the machining and clamping of a thin-walled valve seat;

[0021] Figure 2 A side view of a clamping plate for machining and mounting a thin-walled valve seat;

[0022] Figure 3 A top view of a positioning disc for machining and clamping thin-walled valve seats;

[0023] The attached diagram lists the components represented by each number as follows:

[0024] 10. Fixing part; 101. Mandrel part; 102. Protrusion part; 11. Clamping part; 111. Positioning plate; 112. Through hole; 113. Pressure plate; 12. Positioning hole; 13. Positioning pin; 14. Nut; 15. Threaded hole; 16. Bolt; 17. Mounting hole; 18. Recessed platform; 19. Elastic claw; 191. Arc groove; 192. Center plate. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings.

[0026] like Figure 1 The image shows an embodiment of a thin-walled valve seat machining and clamping method provided by this utility model. In this embodiment, it includes a fixing part and a clamping part, which are detachably connected to the fixing part. The fixing part includes a spindle part and a protrusion part. The surface of the spindle part is provided with multiple sets of positioning holes. The clamping part is connected to the clamping part through a positioning pin. The clamping part includes a positioning plate with a through hole for fixing the positioning pin. The clamping part also includes a pressure plate. One side of the positioning plate contacts the spindle part, and the other side contacts the pressure plate. One side of the pressure plate contacts the positioning plate, and the other side contacts the nut. The clamping part is fixedly connected by the nut and the threaded engagement on the protrusion part.

[0027] In the above technical solution, the mandrel surface is also provided with threaded holes, and the positioning plate is fixedly connected to the mandrel by bolts corresponding to the threaded holes.

[0028] Both the positioning plate and the pressure plate have mounting holes at their centers that are adapted to the size of the protrusion.

[0029] In the above technical solution, a recessed platform is provided on the outer edge of the positioning disk.

[0030] The outer diameter of the pressure plate is matched with the inner diameter of the recess.

[0031] In use, the positioning disc is passed through the mounting hole through the protrusion, so that the through hole of the positioning disc is aligned with the positioning hole of the spindle. The tapered positioning pin (interference fit) is inserted, and then the positioning disc is fixed to the spindle with M8 bolts. The thin-walled valve seat is placed on the protrusion of the spindle, and the end face of the valve seat is in contact with the end face of the concave platform of the positioning disc, which serves as the axial positioning surface to achieve axial positioning.

[0032] like Figure 3 As shown, there are 6-8 independent petal-shaped elastic claws on the outer side of the concave platform. Each elastic claw is connected to the central disk through a circumferentially distributed arc groove. The groove is 2-3mm wide and 2 / 3 the thickness of the pressure plate.

[0033] Among them, the petal-shaped elastic claws of the positioning disc deform independently when the pressure plate is pressed down, adaptively conforming to the irregular contour of the outer wall of the valve seat (such as casting error ±0.1mm), avoiding local stress concentration caused by dimensional deviation.

[0034] The elastic design of the arc groove (the groove depth is 2 / 3 of the platen thickness) gives the claw a rigidity of 10-15 N / mm, which can absorb cutting vibration energy and reduce machining marks.

[0035] The locating pin is a tapered locating pin, which is interference-fitted with the locating hole.

[0036] like Figure 2 As shown, the outer ring of the pressure plate is a wavy curved surface with alternating peaks and troughs, a wave height of 0.3-0.5 mm, and a wavelength of 5-8 mm.

[0037] Among them, the wavy curved surface forms discrete contact points with the inner wall of the valve seat (instead of annular surface contact), and the single-point contact area is small (about 1-2 mm²). Through elastic deformation, the concentrated stress is dispersed into multiple flexible supports, and the measured contact stress is reduced by more than 60%.

[0038] The gap between the crests and troughs (0.4mm) allows the valve seat to undergo slight elastic deformation when clamped, releasing internal residual stress and avoiding plastic deformation caused by rigid compression.

[0039] In use, pass the pressure plate through the mounting hole into the protrusion, and embed the outer ring into the recess of the positioning plate, ensuring that the wavy curved surface faces the inner wall of the valve seat; tighten the nut, and the pressure plate will be pressed down by the nut, causing the wavy curved surface of the pressure plate to press against the inner wall of the valve seat; at the same time, the elastic claw of the positioning plate will expand radially due to the pressure of the pressure plate, further gripping the outer wall of the valve seat; control the tightening torque of the nut with a torque wrench (e.g., 30-40 N·m) to ensure that the pressure plate is pressed down by 0.1-0.2 mm; precision machine the sealing surface and inner hole of the valve seat, and after machining, loosen the nut, remove the pressure plate and positioning plate in sequence, and take out the valve seat.

[0040] It is important to note that if the elastic claws show plastic deformation (such as cracking of the groove), they must be replaced immediately. The claw deformation should be checked after every 500 pieces are processed. When the wear of the wavy pressure plate surface exceeds 0.1mm (the wave height is measured by a feeler gauge), it must be re-ground or replaced to avoid the reduction of clamping force.

[0041] Specifically, the principle of this utility model is as follows: the axial position of the valve seat is fixed by axially pressing the positioning plate (error ≤ 0.02mm). The radial movement is restricted by the clearance fit (H8 / g7) between the protrusion and the inner hole of the valve seat. The interference fit (cone angle 1°-3°) between the positioning pin and the positioning hole eliminates the circumferential clearance and achieves high-precision positioning (radial runout ≤ 0.01mm). The pressure plate is moved inward by tightening the nut, so that the wavy curved surface squeezes the inner wall of the valve seat (multi-point contact). At the same time, the elastic claw of the positioning plate is squeezed by the pressure plate and expands radially to hug the outer wall of the valve seat. At this time, the bidirectional clamping force (inner wall compression + outer wall hugging) is evenly applied to the thin-walled valve seat to counteract the cutting force.

Claims

1. A clamping device for machining thin-walled valve seats, characterized in that, It includes a fixing part and a clamping part, which are detachably connected. The fixing part includes a spindle part and a protrusion part. The surface of the spindle part is provided with multiple sets of positioning holes. The clamping part is connected to the clamping part through a positioning pin. The clamping part includes a positioning plate with a through hole for fixing the positioning pin. The clamping part also includes a pressure plate. One side of the positioning plate contacts the spindle part and the other side contacts the pressure plate. One side of the pressure plate contacts the positioning plate and the other side contacts the nut. The clamping part is fixedly connected by the nut and the threaded engagement on the protrusion part.

2. The thin-walled valve seat machining clamping method according to claim 1, characterized in that, The mandrel surface is also provided with threaded holes, and the positioning plate is fixedly connected to the mandrel by bolts corresponding to the threaded holes.

3. The thin-walled valve seat machining clamping method according to claim 2, characterized in that, Both the positioning plate and the pressure plate have mounting holes at their centers that are adapted to the size of the protrusion.

4. The thin-walled valve seat machining clamping method according to claim 3, characterized in that, The outer edge of the positioning plate has a recessed platform.

5. The clamping device for machining a thin-walled valve seat according to claim 4, characterized in that, The outer diameter of the pressure plate is matched with the inner diameter of the recess.

6. The clamping device for machining a thin-walled valve seat according to claim 5, characterized in that, The outer side of the recessed platform is provided with 6-8 independent petal-shaped elastic claws. Each elastic claw is connected to the central disk through a circumferentially distributed arc groove. The groove is 2-3mm wide and the depth is 2 / 3 of the thickness of the pressure plate.

7. The thin-walled valve seat machining clamping method according to claim 6, characterized in that, The locating pin is a tapered locating pin, which is interference-fitted with the locating hole.

8. The thin-walled valve seat machining clamping device according to claim 7, characterized in that, The outer ring of the pressure plate has a wavy curved surface with alternating peaks and troughs, a wave height of 0.3-0.5mm, and a wavelength of 5-8mm.

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