CN112643373A

CN112643373A - Automatic centering positioning fixture

Info

Publication number: CN112643373A
Application number: CN202011443278.8A
Authority: CN
Inventors: 郁烨侃; 方杭超; 朱健
Original assignee: Hangzhou Good Friend Precision Machinery Co Ltd
Current assignee: Hangzhou Good Friend Precision Machinery Co Ltd
Priority date: 2020-12-08
Filing date: 2020-12-08
Publication date: 2021-04-13

Abstract

The invention discloses an automatic centering positioning fixture, which comprises a left supporting seat and a right supporting seat which are relatively fixed in position, wherein a left chuck is arranged on the left supporting seat, a right chuck is arranged on the right supporting seat, a gear reversing mechanism is fixed on the left supporting seat, and an oil cylinder is fixed on the right supporting seat; the gear reversing mechanism comprises a gear and a rack, the gear comprises a left gear and a right gear which are equal in size and are meshed with each other; the rack comprises a left rack and a right rack which are equal in size and are symmetrically arranged; the left rack is meshed with the left gear, the right rack is meshed with the right gear, and the axes of the left rack and the right rack are overlapped; the oil cylinder is a lateral double-shaft oil cylinder; the left end of the left rack is linked with the left chuck, the right end of the right rack is connected with the left shaft lever of the oil cylinder, and the right shaft lever of the oil cylinder is linked with the right chuck. The invention has the beneficial effects that: the left and right centering of the workpiece can be automatically realized without manual intervention, and the accuracy of workpiece processing is facilitated.

Description

Automatic centering positioning fixture

Technical Field

The invention belongs to the technical field of tool fixtures, and particularly relates to an automatic centering and positioning fixture.

Background

For some workpieces with large sizes and in bilateral symmetry layout, the processing content and the appearance of parts have special position requirements, and if single-side positioning is adopted, the processing of corresponding positions on two sides is difficult to realize centering and equidistant symmetry, such as a front shaft, an axle housing and the like. Chinese patent document CN202877916U discloses "a flying saw fixture device synchronously clamped" in 2013, 4, 17, which includes a base, a slide seat mounted on the base, a synchronous clamping device mounted on the slide seat, and a hydraulic cylinder, where the synchronous clamping device includes a left clamping device, a right clamping device, and a rotary gear, and the left clamping device includes a left clamping block with a left clamping opening on an inner surface of the left slide seat mounted on the left slide seat, and a left rack engaged with the rotary gear; the right clamping device comprises a right slide seat, a right clamping block and a right rack, wherein the right slide seat is arranged on the right slide seat, and the inner surface of the right slide seat is provided with a right clamping opening. The utility model discloses a fly saw fixture device, its simple structure, preparation convenience can be with firm clamp of steel pipe live and automatic centering. The centering realized by the scheme has the central point which takes a longitudinal line passing through the axle center of the rotating gear as a central line. In the case of a clamp used for a large-sized workpiece, the left and right parts of the clamp are not directly connected and fixed, and there is almost no condition to provide a rotary gear as in the aforementioned scheme, thereby making it difficult to apply the scheme.

Disclosure of Invention

Based on the problems, the invention provides an automatic centering and positioning clamp which can automatically realize left and right centering of a workpiece without manual intervention and is beneficial to the accuracy of workpiece processing.

In order to realize the purpose of the invention, the invention adopts the following technical scheme: an automatic centering positioning fixture comprises a left supporting seat and a right supporting seat which are relatively fixed in position, wherein a left chuck is mounted on the left supporting seat, a right chuck is mounted on the right supporting seat, a gear reversing mechanism is fixed on the left supporting seat, and an oil cylinder is fixed on the right supporting seat; the gear reversing mechanism comprises a gear and a rack, the gear comprises a left gear and a right gear which are equal in size and are meshed with each other; the rack comprises a left rack and a right rack which are equal in size and are symmetrically arranged; the left rack is meshed with the left gear, the right rack is meshed with the right gear, and the axes of the left rack and the right rack are overlapped; the oil cylinder is a lateral double-shaft oil cylinder; the left end of the left rack is linked with the left chuck, the right end of the right rack is connected with the left shaft lever of the oil cylinder, and the right shaft lever of the oil cylinder is linked with the right chuck.

The automatic centering positioning fixture designed by the technical scheme comprises two relatively independent parts: the left supporting seat and the right supporting seat are usually fixed on the same horizontal plane of the workbench in opposite positions. The left support seat is provided with a left chuck, the right support seat is provided with a right chuck, and the left chuck and the right chuck are in direct contact with a workpiece and are usually clamped at two end parts of the workpiece in the length direction respectively. Wherein, a gear reversing mechanism is fixed on the left supporting seat, an oil cylinder is fixed on the right supporting seat, and the positions of the two can be interchanged. The gear reversing mechanism comprises two gears and two racks. The two gears have the same size, model and specification and are meshed with each other; the two racks are identical in size, model and specification, symmetrically arranged and meshed with one gear respectively, and the axes of the two racks are overlapped. In the structure, both sides comprise a gear and are meshed with a rack, and the gears on both sides are also meshed with each other, so that the rack on any side moves along the axial direction, and the opposite racks move in opposite directions and equal amplitude through the gear on the side and the opposite gear. The oil cylinder is a lateral double-shaft type oil cylinder and is provided with a piston and two shaft rods, the two shaft rods are coaxially arranged and extend in the lateral direction of the oil cylinder, the motion amplitudes are the same, but the directions are opposite, and oil can be injected into or pumped out of the oil cylinder through automatic operation to realize the reverse same-amplitude motion of the two shaft rods of the oil cylinder. The oil cylinder can also be replaced by other existing devices such as other fluid cylinders with the same motion characteristics and capable of realizing automatic control. In the power connection system, the left end of the left rack is linked with the left chuck, the right end of the right rack is connected with the left shaft lever of the oil cylinder, and the right shaft lever of the oil cylinder is linked with the right chuck. The oil liquid of the oil cylinder is controlled to be injected or extracted, so that the two shaft levers of the oil cylinder can be controlled to stretch, the shaft lever on the left side is connected with the right rack of the gear reversing mechanism, the reversing is realized through the gear reversing mechanism, the left rack of the gear reversing mechanism is driven to move, and the left rack and the right shaft lever of the oil cylinder are the same in movement amplitude and opposite in direction. The left end of the left rack is linked with the left chuck, the right shaft lever of the oil cylinder is linked with the right chuck, and the left chuck and the right chuck are driven to move in opposite directions and in the same amplitude by the actions. The workpiece clamped by the left chuck and the right chuck can be always positioned in automatic centering and positioning, so that the automatic machining is facilitated, and the machining precision is improved.

Preferably, the gear reversing mechanism is further provided with a shell, a left fixing bushing and a right fixing bushing are installed in the shell, and the cross sections of the left fixing bushing and the right fixing bushing are the same; the left rack is sleeved in the left fixed bushing in a matched mode and can slide left and right, and the right rack is sleeved in the right fixed bushing in a matched mode and can slide left and right. The meshing part is coated in the shell, so that the interference of the outside to the meshing action is eliminated, and the reversing can be kept accurate and sensitive. Install left fixed bush and right fixed bush in the shell, mainly used forms the guide effect, and the better edge axial of help left rack and right rack is flexible.

Preferably, two mandrels are fixedly arranged in the shell, and the left gear and the right gear are respectively sleeved on one of the mandrels; two ends of the mandrel are respectively provided with a ball bearing, and the outer side of each ball bearing is fixedly provided with an end cover; the inner side end of the ball bearing inner ring is abutted against the end surface of the left gear or the right gear, and the outer side end of the ball bearing outer ring is abutted against the inner side surface of the end cover. The dabber is fixed the setting, and left gear and right gear overlap respectively and establish on one of them dabber and realize the meshing. Two ends of each mandrel are respectively provided with a ball bearing, the inner side end of the inner ring of each ball bearing abuts against the end surface of the left gear or the right gear, and the outer side end of the outer ring abuts against the end cover, so that the rotation of the left gear and the right gear which are sleeved on the mandrels is changed into the rotation friction of the ball bearings from sliding friction. Not only the friction coefficient is obviously reduced, but also the rotation precision is improved, so that the reversing action is more accurate.

Preferably, the left rack and the right rack are provided with limit grooves, and the length direction of the limit grooves extends along the moving direction of the left rack and the right rack; be equipped with spacing bolt hole on the shell, spacing bolt wears to establish in spacing bolt hole, and the tip is deep into the spacing groove. The limiting groove is matched with the limiting bolt, so that the maximum amplitude of the axial motion of the left rack and the right rack is limited, and a protection mechanism is formed.

Preferably, the ball bearing is a deep groove ball bearing. The deep groove ball bearing has the characteristics of small friction resistance, high rotating speed and capability of better bearing axial load, so that rolling friction of the left gear and the right gear can be better facilitated.

Preferably, the device further comprises an adjusting connecting rod; the length of the adjusting connecting rod is adjustable, and two ends of the adjusting connecting rod are respectively connected with the right end of the right rack and the left shaft lever of the oil cylinder. The length of the adjusting connecting rod is adjustable, and the adjusting connecting rod is used for connecting the right end of the right rack and the left shaft lever of the oil cylinder, so that force transmission in a long distance is realized.

Preferably, a lever driving structure is connected between the left end of the left rack and the left chuck; the lever driving structure comprises a lower connecting rod, a swinging rod and an upper connecting rod, and the middle part of the swinging rod is rotatably connected to the left supporting seat through a pin shaft; the right end of the lower connecting rod is hinged with the left end of the left rack, the left end of the lower connecting rod is hinged with the lower end of the oscillating rod, the left end of the upper connecting rod is hinged with the upper end of the oscillating rod, and the right end of the upper connecting rod is linked with the left chuck; the same lever driving structure is connected between the right shaft lever of the oil cylinder and the right chuck. The scheme designs a lever driving structure, a swing rod fixed and rotatable in the middle is used as a lever in the lever driving structure, a lower connecting rod is used as a force application side, an upper connecting rod is used as a stress side, and the lower connecting rod is pulled to drive the upper connecting rod to move through the swing rod. And lever driving structures with the same specification are arranged between the left end of the left rack and the left chuck and between the right shaft lever of the oil cylinder and the right chuck, so that when the left end of the left rack and the right shaft lever of the oil cylinder act in the opposite directions with the same amplitude, the left chuck and the right chuck can be driven to act in the opposite directions with the same amplitude through the same lever driving structure.

Preferably, the hinge hole at the upper end of the swing rod is a long hole, and the length direction of the hinge hole extends along the length direction of the swing rod; the supporting seat is provided with an upper connecting rod guide hole extending in the left-right direction, the aperture of the upper connecting rod guide hole is matched with the section of the upper connecting rod, and the upper connecting rod can slide left and right in the upper connecting rod guide hole. The upper connecting rod is hinged with the swing rod, and driven by the swing action of the swing rod, the upper connecting rod does not perform complete left-right movement and also performs partial up-down movement, so that the upper connecting rod is required to eliminate the up-down movement by designing a hinge hole at the upper end of the swing rod into a long hole, and the upper connecting rod is simultaneously assisted with the guiding of a guide hole of the upper connecting rod to ensure that the upper connecting rod only performs the left-right movement. The left chuck and the right chuck are driven by the left upper connecting rod and the right upper connecting rod to move only left and right, and the clamping effect is ensured.

In conclusion, the beneficial effects of the invention are as follows: the left and right centering of the workpiece can be automatically realized without manual intervention, and the accuracy of workpiece processing is facilitated.

Drawings

Fig. 1 is a top view of the present invention.

Fig. 2 is an X-X sectional view of fig. 1.

Fig. 3 is a schematic perspective view of the gear reversing mechanism.

Fig. 4 is a top view of fig. 3.

Fig. 5 is a sectional view a-a of fig. 4.

Fig. 6 is a sectional view B-B of fig. 4.

Wherein: 1 workbench, 2 left supporting seats, 3 right supporting seats, 4 left chucks, 5 right chucks, 6 gear reversing mechanisms, 60 shells, 61 left gears, 62 right gears, 63 left racks, 64 right racks, 65 left fixing bushes, 66 right fixing bushes, 67 mandrels, 68 ball bearings, 69 end covers, 7 adjusting connecting rods, 8 oil cylinders, 9 lower connecting rods, 10 oscillating rods, 11 upper connecting rods and 99 workpieces.

Detailed Description

The invention is further described with reference to the following detailed description and accompanying drawings.

The embodiment relates to an automatic centering positioning fixture which is applied to automatic machining operation of certain large-sized workpieces.

As shown in fig. 1 and 2, the automatic centering and positioning fixture of the present embodiment is mounted on a horizontally placed work table 1, and includes a left support base 2 located on the left side and a right support base 3 located on the right side, and the positions of the two are relatively fixed. A gear reversing mechanism 6 is fixed on the left support seat 2, and an oil cylinder 8 is fixed on the right support seat 3.

As shown in fig. 3 and 4, the gear reversing mechanism 6 in this embodiment includes a housing 60, and the housing 60 is fixed on the table top through a base. The housing is shaped like a rectangular parallelepiped, and the longitudinal direction extends in the left-right direction of fig. 2. The left and right sides of the housing 60 respectively extend out of a left rack 63 and a right rack 64, the left end of the left rack 63 and the right end of the right rack 64 are both provided with a transmission connecting structure, the transmission connecting structure in this example is a transmission rod, the root of the transmission rod is fixed with the left end of the left rack 63 or the right end of the right rack 64 through threads, the end part of the transmission rod is provided with a longitudinal slot, and bolt holes are arranged on two side walls of the slot in a penetrating manner for standby.

As shown in fig. 5, two gears and two racks are installed in the housing: the left gear 61 and the right gear 62 are identical in size, model and specification and are meshed with each other; the two racks of the left rack 63 and the right rack 64 have the same size, model and specification and are symmetrically arranged; the left rack 63 meshes with the left gear 61, the right rack 64 meshes with the right gear 62, and the axes of the left rack 63 and the right rack 64 coincide. The left end of the left rack 63 protrudes to the left of the housing 60, and the right end of the right rack 64 protrudes to the right of the housing 60. The left side is fixed with left fixed bush 65 in the shell 60, and the right side is fixed with right fixed bush 66, and both's cross sectional shape is the same, also is the same with the cross sectional shape of left rack 63 or right rack 64, therefore, the left rack 63 adaptation is located and can be slided from side to side in left fixed bush 65, and the right rack 64 adaptation is located and can be slided from side to side in right fixed bush 66.

The rack is also provided with a protection structure. Taking the left rack 63 as an example, the top of the left rack 63 is provided with a limiting groove 631 with an upward opening, and the length direction of the limiting groove 631 extends along the left rack 63, i.e., the left-right direction. Correspondingly, a limiting bolt hole is correspondingly formed in the shell 60, the limiting bolt 601 penetrates through the limiting bolt hole from top to bottom, and the end part of the lower end penetrates into the limiting groove 631. Therefore, when the left rack 63 slides left and right, the sliding range is limited by the length of the limiting groove 631. The shape and size of the limit groove 631 of the right rack 64 are completely symmetrical to those of the limit groove 631 of the left rack 63.

As shown in fig. 6, two mandrels 67 are fixedly installed on the left and right sides in the housing 60, and the left gear 61 and the right gear 62 are respectively sleeved on the left mandrel 67 and the right mandrel 67. Taking the left mandrel 67 as an example, two ball bearings 68 are respectively mounted at two ends of the mandrel 67, and the ball bearings 68 in this example are deep groove ball bearings. An end cover 69 is fixedly arranged on the outer side of the ball bearing 68 to facilitate disassembly and assembly. The inner end of the inner ring of the ball bearing 68 abuts the end face of the left gear 61, and the outer end of the outer ring of the ball bearing 68 abuts the inner face of the end cap 69.

The cylinders 8 in this example are side biaxial type cylinders, and the labels are yuwan linkage and their model numbers HTB-SW63 × 40N in taiwan. The oil cylinder 8 of the embodiment is provided with a piston and two shaft levers, the two shaft levers are coaxially arranged and respectively extend and retract in the left side direction and the right side direction of the oil cylinder, the movement amplitudes are the same, but the directions are opposite, and the oil can be injected into or pumped out of the oil cylinder through automatic operation to realize the reverse same-amplitude movement of the two shaft levers.

Install left chuck 4 on the left side supporting seat 2, be connected with lever drive structure between the left end of left rack 63 and the left chuck 4, specifically as follows: the lever driving structure comprises a lower connecting rod 9, a swinging rod 10 and an upper connecting rod 11, wherein the lower connecting rod 9 extends leftwards and rightwards, the right end of the lower connecting rod is hinged with the left end of the left rack 63, and the left end of the lower connecting rod is hinged with the lower end of the swinging rod 10; the swing rod 10 extends upwards and downwards, the middle part of the swing rod is fixed on the left supporting seat 2 in a rotatable mode through a pin shaft, the lower end of the swing rod is hinged with the left end of the lower connecting rod 9, and the upper end of the swing rod is hinged with the left end of the upper connecting rod 11. The hinge hole at the upper end of the swing lever 10 is a long hole, and the length direction extends along the length direction of the swing lever 10. The supporting seat 2 is provided with an upper connecting rod guide hole extending in the left-right direction, and the aperture of the upper connecting rod guide hole is matched with the section of the upper connecting rod 11, so that the upper connecting rod 11 can only slide left and right in the upper connecting rod guide hole.

The right supporting seat 3 is symmetrically provided with a right clamping head 5. The same lever driving structure is connected between the right shaft lever of the oil cylinder 8 and the right chuck 5, the lever driving structure is completely symmetrical and consistent with the structure on the left side, and only the left end of the left rack 63 is replaced by the right shaft lever of the oil cylinder 8.

Hard connection is realized between the right end of the right rack 64 and the left shaft lever of the oil cylinder 8 by the adjusting connecting rod 7 extending in the left-right direction, and the length of the adjusting connecting rod 7 is adjustable and can be adapted to be arranged on different intervals between the gear reversing mechanism 6 and the oil cylinder.

In the automatic centering and positioning clamp of the embodiment, all driving actions do not need manual intervention, and only oil is injected into or pumped out of the oil cylinder 8 in a control mode. When the hydraulic oil pumping device is used, oil is injected into the oil cylinder 8 through automatic control, and the left shaft lever and the right shaft lever of the oil cylinder 8 move in opposite directions with the same amplitude after the oil pressure rises. In the left direction, the left shaft lever of the oil cylinder 8 is connected to the right end of the right rack 64 through the adjusting connecting rod 7 to drive the right rack 64 to translate leftwards, and the leftward translation action of the right rack 64 is changed into rightward same-amplitude translation of the left rack 63 through the gear reversing mechanism 6. The left rack 63 drives the lower connecting rod 9 in the left lever driving structure to move rightwards, the lower connecting rod 9 drives the upper connecting rod 11 to move leftwards through the swinging rod 10, and finally the left chuck 4 moves leftwards. In the right direction, the right shaft lever of the oil cylinder 8 directly drives the lower connecting rod 9 in the right lever driving structure to move leftwards, the lower connecting rod 9 drives the upper connecting rod 11 to move rightwards through the swinging rod 10, and finally the right chuck 5 moves rightwards. The left chuck 4 moves leftwards, the right chuck 5 moves rightwards, the moving amplitude of the left chuck 4 and the moving amplitude of the right chuck 5 are equal, the moving directions are opposite, the workpiece 99 clamped between the left chuck 4 and the right chuck 5 is always in an automatic centering and positioning posture, and the subsequent processing progress can be effectively guaranteed.

Claims

1. An automatic centering positioning fixture comprises a left supporting seat (2) and a right supporting seat (3) which are relatively fixed in position, wherein a left chuck (4) is installed on the left supporting seat (2), and a right chuck (5) is installed on the right supporting seat (3), and is characterized in that a gear reversing mechanism (6) is fixed on the left supporting seat (2), and an oil cylinder (8) is fixed on the right supporting seat (3); the gear reversing mechanism (6) comprises a gear and a rack, wherein the gear comprises a left gear (61) and a right gear (62) which are equal in size and are meshed with each other; the racks comprise a left rack (63) and a right rack (64), and the left rack and the right rack are equal in size and are symmetrically arranged; the left rack (63) is meshed with the left gear (61), the right rack (64) is meshed with the right gear (62), and the axes of the left rack (63) and the right rack (64) are superposed; the oil cylinder (8) is a lateral double-shaft oil cylinder; the left end of the left rack (63) is linked with the left chuck (4), the right end of the right rack (64) is connected with the left shaft lever of the oil cylinder (8), and the right shaft lever of the oil cylinder (8) is linked with the right chuck (5).

2. The automatic centering and positioning clamp as claimed in claim 1, wherein the gear reversing mechanism (6) is further provided with a housing (60), a left fixing bush (65) and a right fixing bush (66) are installed in the housing, and the cross sections of the left fixing bush and the right fixing bush are the same; the left rack (63) is sleeved in the left fixed bushing (65) in a matching way and can slide left and right, and the right rack (64) is sleeved in the right fixed bushing (66) in a matching way and can slide left and right.

3. The automatic centering and positioning fixture as claimed in claim 2, wherein two mandrels (67) are fixedly mounted in the housing (60), and the left gear (61) and the right gear (62) are respectively sleeved on one of the mandrels (67); two ends of the mandrel (67) are respectively provided with a ball bearing (68), and the outer side of each ball bearing (68) is fixedly provided with an end cover (69); the inner end of the inner ring of the ball bearing (68) is abutted against the end surface of the left gear (61) or the right gear (62), and the outer end of the outer ring of the ball bearing (68) is abutted against the inner side surface of the end cover (69).

4. The automatic centering and positioning clamp as claimed in claim 3, wherein the left rack (63) and the right rack (64) are provided with limit grooves (631), and the length direction of the limit grooves (631) extends along the moving direction of the left rack (63) and the right rack (64); the shell (60) is provided with a limit bolt hole, the limit bolt (601) penetrates through the limit bolt hole, and the end part of the limit bolt penetrates into the limit groove (631).

5. An automatic centering and positioning fixture as claimed in claim 3 or 4, characterized in that said ball bearings (68) are deep groove ball bearings.

6. A self-centring and positioning clamp as claimed in claim 1 or 2 or 3 or 4, characterized by further comprising an adjusting link (7); the length of the adjusting connecting rod (7) is adjustable, and two ends of the adjusting connecting rod are respectively connected with the right end of the right rack (64) and the left shaft lever of the oil cylinder (8).

7. An automatic centering and positioning clamp as claimed in claim 1, 2, 3 or 4, wherein a lever driving structure is connected between the left end of the left rack (63) and the left chuck (4); the lever driving structure comprises a lower connecting rod (9), a swinging rod (10) and an upper connecting rod (11), and the middle part of the swinging rod (10) is rotatably connected to the left supporting seat (2) through a pin shaft; the right end of the lower connecting rod (9) is hinged with the left end of the left rack (63), the left end of the lower connecting rod (9) is hinged with the lower end of the oscillating rod (10), the left end of the upper connecting rod (11) is hinged with the upper end of the oscillating rod (10), and the right end of the upper connecting rod (11) is linked with the left chuck (4); the same lever driving structure is connected between the right shaft lever of the oil cylinder (8) and the right chuck (5).

8. The automatic centering and positioning clamp as claimed in claim 7, wherein the hinge hole at the upper end of the swing lever (10) is a long hole, and the length direction of the long hole extends along the length direction of the swing lever (10); an upper connecting rod guide hole extending in the left-right direction is formed in the supporting seat (2), the aperture of the upper connecting rod guide hole is matched with the section of the upper connecting rod (11), and the upper connecting rod (11) can slide left and right in the upper connecting rod guide hole.