CN112727290B

CN112727290B - Door opener and closer with force adjustment device

Info

Publication number: CN112727290B
Application number: CN202011395879.6A
Authority: CN
Inventors: 戚志; 黎善雄
Original assignee: Guangdong Jusen Precision Technology Co ltd
Current assignee: Guangdong Jusen Precision Technology Co ltd
Priority date: 2020-12-03
Filing date: 2020-12-03
Publication date: 2025-03-11
Anticipated expiration: 2040-12-03
Also published as: CN112727290A

Abstract

The present invention discloses a door body opener and closer with a force adjustment device, comprising a housing, a driving device and a force adjustment device arranged in the housing, wherein: the driving device comprises a first set of rods and a second set of rods, the first set of rods is provided with a first spring, and the second set of rods is provided with a second spring; the force adjustment device comprises an adjustment screw, an adjustment lever and an adjustment spring, the adjustment spring is arranged in the deformation direction of the second spring, one end of the adjustment lever compresses the adjustment spring, and the other end cooperates with the adjustment nut, and the adjustment nut moves along the axial direction of the adjustment screw. The present invention is provided with a force adjustment device, and the user rotates the adjustment screw to adjust the swing of the adjustment lever to compress the adjustment spring, thereby realizing that the user can adjust the damping force of the door body opener and closer by himself.

Description

Door shutter with force adjusting device

Technical Field

The invention belongs to the field of furniture hardware accessories, and particularly relates to a door shutter with a force adjusting device.

Background

The chinese patent document CN10976376 a discloses a door opener, which comprises a casing composed of an upper cover plate and a lower cover plate, wherein a pushing device for pushing the door to rotate is arranged in the casing, one end of a driving device with a spring drives the pushing device to rotate through a rotating part, and a locking release device matched with the driving device is arranged at the other end of the driving device.

The scheme ensures that the vertical hinged door is more convenient to open and close, but the damping in the opening and closing process of the door body is not adjustable, so that the use experience of a user is seriously influenced. For this purpose, it is necessary to optimize the door shutter.

Disclosure of Invention

The invention aims to provide a door shutter with a force adjusting device, which can realize that a user can automatically adjust the damping force of the door shutter.

The technical problems are solved by the following technical scheme: the utility model provides a door body shutter with dynamics adjusting device, includes the casing, is equipped with drive arrangement and dynamics adjusting device in the casing, wherein:

The driving device comprises a first loop bar and a second loop bar, the first loop bar is sleeved with a first spring, and the second loop bar is sleeved with a second spring;

the force adjusting device comprises an adjusting screw, an adjusting lever and an adjusting spring, wherein the adjusting spring is arranged in the deformation direction of the second spring, one end of the adjusting lever compresses the adjusting spring, the other end of the adjusting lever is matched with an adjusting nut, and the adjusting nut axially moves along the adjusting screw.

Compared with the background technology, the invention has the beneficial effects that the damping force adjusting device is arranged, and a user can adjust the damping force of the shutter of the door body by himself by rotating the adjusting screw and adjusting the swinging of the lever to compress the adjusting spring.

In one embodiment, the adjusting spring is sleeved on the second sleeve rod, and the second sleeve rod is provided with a rod body convex ring for separating the adjusting spring and the second spring.

The adjusting spring and the second spring are sleeved on the second loop bar and separated through the convex rings of the bar body, and the adjusting spring and the second spring are simple and compact in structure.

In one embodiment, the second sleeve rod slides axially along the housing, and the adjustment lever pushes the second sleeve rod and compresses the adjustment spring.

The adjustable spring compression device has the beneficial effects that the compression of the adjusting spring is realized through the sliding of the second loop bar, the structure is simple and reliable, and the cost is low.

In one embodiment, the force adjusting device comprises a force indicating piece and a force indicating hole, wherein the force indicating hole is formed in the shell, force scales are arranged on the edge of the force indicating hole, and the adjusting lever pushes the force indicating piece to reciprocate in the force indicating hole.

The damping strength indicator has the beneficial effects that the setting of the strength indicator enables a user to intuitively know the damping strength of the door shutter, and the teaching convenience is improved.

In one embodiment, the first loop bar and the second loop bar are arranged in parallel, the first loop bar axially slides along the shell and is sleeved with the first sliding sleeve, and the second loop bar is sleeved with the second sliding sleeve.

The double-sliding-sleeve type door has the beneficial effects that the double-sliding-sleeve design is adopted, the acting force of the first spring and the acting force of the second spring are convenient to adjust independently, and the damping schedulability in the opening and closing process of the door body is improved.

In one embodiment, the shell clamps the first sliding sleeve and the second sliding sleeve, the first sliding sleeve is in sliding fit with the second sliding sleeve, a sliding sleeve cavity is formed by the first sliding sleeve and the second sliding sleeve, a cavity spring is arranged in the sliding sleeve cavity, and the first sliding sleeve is in linkage with the second sliding sleeve through the cavity spring.

The sliding sleeve has the beneficial effects that acting force between the first sliding sleeve and the second sliding sleeve is transmitted through the cavity spring, so that the first sliding sleeve and the second sliding sleeve are flexibly and slidably connected.

In one embodiment, the housing is provided with a door pushing device, the door pushing device comprises a push rod for pushing the door body to rotate, the root of the push rod is a cam, the cam is provided with a cam groove and a cam rod, a sleeve rod shifting fork is coaxially arranged with the cam, and the cam drives the sleeve rod shifting fork through the cam rod, so that the sleeve rod shifting fork drives the first sleeve rod.

In one embodiment, the cam is composed of two overlapped cam plates, a cam clamping groove is formed between the two cam plates, the loop bar shifting fork is arranged in the cam clamping groove, and the cam bar is arranged in the cam clamping groove and connected with the two cam plates.

In one embodiment, the cam of the door pushing device pushes the first sliding sleeve to compress the first spring through the first rotating piece, and pushes the second sliding sleeve to compress the second spring through the second rotating piece.

In one embodiment, the first rotating and swinging part and the second rotating and swinging part are respectively composed of a bearing seat, a bearing and a supporting seat, one end of the bearing seat and the supporting seat are connected with the shell through shaft pins, the other two ends of the bearing seat are respectively connected with the bearing, the surface of the bearing seat is provided with a bearing seat groove, the surface of the supporting seat is provided with a supporting seat boss, the bearing seat groove and the supporting seat boss are embedded and positioned, and the two supporting seats are tightly attached to each other and in sliding fit.

The above embodiments can be arbitrarily combined to form a combined embodiment on the premise that the technical schemes are not contradictory according to the design requirements of the products.

Drawings

FIG. 1 is a schematic view of the internal structure of the present invention;

FIG. 2 is an exploded view of the structure of the present invention;

FIG. 3 is a partial exploded view of the present invention;

FIG. 4 is a schematic view of a door pushing device according to the present invention;

FIG. 5 is a schematic view of the construction of a first loop bar of the present invention;

FIG. 6 is a schematic view showing the change of the operating state of the lock release device according to the present invention;

FIG. 7 is a schematic structural view of a first sliding sleeve and a second sliding sleeve according to the present invention;

FIG. 8 is a schematic view of a buffer device according to the present invention;

FIG. 9 is a schematic view of a force adjusting device according to the present invention;

FIG. 10 is a schematic diagram showing the change of the operating state of the force adjusting device according to the present invention;

FIG. 11 is a schematic view of the structure of the present invention in the first operating state;

FIG. 12 is a schematic view of the structure of the second working state of the present invention;

FIG. 13 is a schematic view of the structure of the present invention in the third operating state;

FIG. 14 is a schematic view of the structure of the present invention in the fourth operating state;

fig. 15 is a schematic structural view of the present invention in the fifth working state.

The door pushing device comprises a door pushing device, a first rotating piece 11, a bearing seat 11a, a bearing seat 11b, a supporting seat 11c, a bearing seat groove 11d, a supporting seat boss 11e, a second rotating piece 12a, a bearing seat 12b, a supporting seat 12c, a bearing seat groove 12d, a supporting seat boss 12e, a cam 13, a cam groove 13a, a cam rod 13b, a cam clamping groove 13c, a14 shaft pin, a 15 sleeve rod shifting fork, a 16 push rod and a 17 push rod sliding block;

The driving device comprises a driving device, a first sleeve rod, a first spring, a first sliding sleeve, a 21c shifting rod section, a 21d driving sliding block, a second sleeve rod, a second spring, a second sliding sleeve, a convex ring of a rod body, a 23 sliding sleeve cavity, a 24 cavity spring, a 25 sliding sleeve groove and a 26 shell convex edge, wherein the driving device comprises a first sleeve rod, a 21a first spring, a 21b first sliding sleeve, a 21c shifting rod section and a 21d driving sliding block;

3 a locking release device, 31a stop, 31a blocking part, 31b locking part, 32 locking damper, 33 latch hook, 34 releasing push block;

4 buffer devices, 41 buffer blocks, 41a balance guide plates, 41b sliding limit plates, 41c shifting fork limit plates, 42 buffer dampers and 43 buffer shifting forks;

5 dynamics adjusting device, 51 adjusting screw, 52 adjusting lever, 53 adjusting spring, 54 adjusting nut, 55 dynamics indicating piece, 56 dynamics indicating hole.

Detailed Description

The following describes in further detail the embodiments of the present invention with reference to the drawings and examples. The following examples are illustrative of the invention and are not intended to limit the scope of the invention.

As shown in fig. 1 to 10, the door shutter of the present embodiment includes a housing in which a door pushing device 1, a driving device 2, a lock release device 3, a buffer device 4, and a force adjusting device 5 are provided.

As shown in fig. 1 to 4, the push door device 1 includes a first swing piece 11, a second swing piece 12, a cam 13, a shaft pin 14, a stem fork 15, a push rod 16, and a push rod slider 17. The door pushing device 1 is connected with the driving device 2 through the first rotating and swinging piece 11 and the second rotating and swinging piece 12, and pushes the door body to rotate.

The first rotary swinging part 11 and the second rotary swinging part 12 are arranged side by side and are fixed in the shell through the same shaft pin 14, and synchronously rotate around the shaft. The first rotating and swinging piece 11 and the second rotating and swinging piece 12 are respectively composed of bearing blocks 11a and 12a, bearings 11b and 12b and supporting seats 11c and 12c, the bearing blocks 11a and 12a are of triangular structures, one end of each bearing block 11a and 12a and each supporting seat 11c and 12c are connected with a shell shaft through shaft pins 14, the other two ends of each bearing block are respectively connected with the bearings 11b and 12b, bearing block grooves 11d and 12d are formed in the surfaces of the bearing blocks 11a and 12a, supporting seat bosses 11e and 12e are formed in the surfaces of the supporting seats 11c and 12c, the bearing block grooves 11d and 12d are embedded and positioned with the supporting seat bosses 11e and 12e, and the two supporting seats 11c and 12c are tightly attached to each other and are in sliding fit with each other.

The push rod 16 of the door pushing device 1 is used for pushing the door body to rotate, and the cam 13 is arranged at the root of the push rod 16. The cam 13 is provided with a cam groove 13a and a cam rod 13b, a set of lever fork 15 is coaxially arranged with the cam 13, and the cam 13 toggles the lever fork 15 through the cam rod 13b, so that the lever fork 15 toggles the first lever 21. The push rod 16 is sleeved with the push rod sliding block 17 and is in sliding fit, and the push rod sliding block 17 is connected with the door body bracket shaft.

The cam 13 is composed of two overlapped cam pieces, a cam clamping groove 13c is formed between the two cam pieces, a loop bar shifting fork 15 is arranged in the cam clamping groove 13c, and a cam bar 13b is arranged in the cam clamping groove 13c and is connected with the two cam pieces.

As shown in fig. 1-3, the driving device 2 comprises a first set of bars 21 and a second set of bars 22 arranged in parallel. As shown in fig. 5, the first stem 21 is provided with a first spring 21a, a first slide bush 21b, a lever section 21c and a drive slider 21d. The first sleeve rod 21 slides along the axial direction of the housing, and the first spring 21a and the first sliding sleeve 21b are sleeved on the first sleeve rod 21. The shift rod section 21c and the driving slider 21d are located at the end-to-end ends of the first sleeve rod 21, and the first spring 21a is sandwiched between the first slide sleeve 21b and the driving slider 21d.

The second sleeve rod 22 is sleeved with a second spring 22a and a second sliding sleeve 22b, the first rotating and swinging piece 11 pushes the first sliding sleeve 21b to compress the first spring 21a, the second rotating and swinging piece 12 pushes the second sliding sleeve 22b to compress the second spring 22a, and the locking and releasing device 3 is used for locking and releasing the first sleeve rod 21.

As shown in fig. 7, the first sliding sleeve 21b and the second sliding sleeve 22b are respectively provided with a sliding sleeve groove 25, the housing is provided with a housing rib 26, the housing clamps the first sliding sleeve 21b and the second sliding sleeve 22b, and the sliding sleeve groove 25 is in sliding fit with the housing rib 26. Simultaneously, the first sliding sleeve 21b and the second sliding sleeve 22b are in sliding fit, a sliding sleeve cavity 23 is formed by the first sliding sleeve 21b and the second sliding sleeve 22b, a cavity spring 24 is arranged in the sliding sleeve cavity 23, and the first sliding sleeve 21b and the second sliding sleeve 22b are in linkage through the cavity spring 24. The sliding sleeve cavity 23 is positioned between the first sleeve rod 21 and the second sleeve rod 22, and the first rotary swinging piece 11 and the second rotary swinging piece 12 respectively abut against the sliding sleeve cavity 23.

As shown in fig. 6, the lock release device 3 includes a stopper 31, a lock damper 32, a lock hook 33, and a release push block 34, where the stopper 31 is rotatable and is provided with a blocking portion 31a and a locking portion 31b in a bifurcated manner, the blocking portion 31a is provided with a blocking end surface that blocks the first loop bar 21, the blocking end surface is an obtuse end surface, the driving slider 21d is engaged with the blocking end surface, the lock damper 32 is located on a rotation locus of the blocking portion 31a, the lock hook 33 is located on a rotation locus of the locking portion 31b and is engaged with the locking portion 31b in a hooking manner, and the release push block 34 controls release of the lock hook 33 and the locking portion 31 b.

The blocking portion 31a is provided with a sliding end surface for sliding a driving slide block 21d of the first sleeve rod 21, an obtuse angle end surface is positioned at the tail end of the sliding end surface, the locking damper 32 is clamped between the blocking portion 31a and the locking portion 31b, the locking hook 33 is rotatable, a hook-fastening end of the locking hook 33 is hooked with the locking portion 31b, a pressing end of the locking hook 33 is in contact fit with the release push block 34, and the locking hook 33 and the release push block 34 are respectively provided with a reset spring. The pressing end of the latch hook 33 is snapped into the release groove of the release push block 34, and the return spring drives the hooking end of the latch hook 33 to rotate clockwise. The release groove is axially arranged on the side wall of the release push block 34, and the reset spring drives the release push block 34 to axially move.

As shown in fig. 1 to 4, the damper device 4 includes a damper block 41, a damper 42, and a damper fork 43. One end of the buffer damper 42 is fixed on the shell, the other end is matched with the buffer block 41, and the buffer block 41 is arranged in a buffer sliding groove of the shell to slide in a reciprocating manner. The buffer shifting fork 43 is positioned between the first rotating and swinging parts 11 and 12, a shifting fork gap is reserved between the supporting seats 11c and 12c of the two rotating and swinging parts, the buffer shifting fork 43 is arranged in the shifting fork gap, the first rotating and swinging part 11, the second rotating and swinging part 12 and the buffer shifting fork 43 are coaxially arranged (namely, are connected with a shell shaft through shaft pins 14), and the buffer shifting fork 43 is pushed by the first rotating and swinging part 11 or the second rotating and swinging part 12 through bearings, so that the buffer shifting fork 43 shifts the buffer block 41.

As shown in fig. 8, the buffer block 41 has an arc structure, the buffer block 41 is provided with a sliding limit piece 41b, a balance guide piece 41a and a shifting fork limit piece 41c, the balance guide piece 41a is positioned on the arc inner circle side, the sliding limit piece 41b is positioned on the arc top end, and the shifting fork limit piece 41c is positioned on the arc middle part and the tail end. The buffer slide groove is an arc-shaped groove, and the shell clamps the buffer block 41 in the buffer slide groove. The buffer sliding chute is provided with a sliding chute limiting piece, a guide hole and a shifting fork hole, the sliding limiting piece 41b is matched with the sliding chute limiting piece, the balance guide piece 41a is clamped in the guide hole, and the buffer shifting fork 43 penetrates through the shifting fork hole and is matched with the shifting fork limiting piece 41 c. Further, the buffer fork 43 is provided with a first fork end and a second fork end, the first fork end is located on the rotation track of the first rotary swing part 11 or the second rotary swing part 12 and is matched with the bearing, and the second fork end is located on the movement track of the buffer block 41 and is alternately matched with the two fork limiting plates 41c of the buffer block 41.

As shown in fig. 9 to 10, the force adjusting device 5 includes an adjusting screw 51, an adjusting lever 52 and an adjusting spring 53, the adjusting spring 53 is sleeved on the second sleeve 22 and separated from the second spring 22a by a rod body convex ring 22c on the second sleeve 22, one end of the adjusting lever 52 compresses the adjusting spring 53, the other end is matched with an adjusting nut 54, and the adjusting nut 54 moves axially along the adjusting screw 51. The second sleeve 22 slides axially along the housing, and the adjustment lever 52 pushes the second sleeve 22 and compresses the adjustment spring 53.

The force adjusting device 5 comprises a force indicating piece 55 and a force indicating hole 56, wherein the force indicating hole 56 is formed in the shell, as shown in fig. 1-3, force scales are arranged at the edge of the force indicating hole 56, and the adjusting lever 52 pushes the force indicating piece 55 to reciprocate in the force indicating hole 56.

The working principle of the invention is described below by taking the working cycle of opening-closing-opening the door body as an example:

Initially, as shown in fig. 11, the door body is in an open state, at this time, the buffer block 41 is ejected out of the housing by the buffer damper 42, the first swing piece 11 and the second swing piece 12 are respectively pushed into the cam groove 13a of the door pushing device 1 by the first sliding sleeve 21b and the second sliding sleeve 22b under the action of the first spring 21a and the second spring 22a, and the blocking portion 31a of the stop block 31 of the lock release device 3 abuts against the driving slider 21d of the first loop bar 21, and the loop bar fork 15 abuts against the pulling bar section 21c of the first loop bar 21.

When the door body is closed, as shown in fig. 12, the door body rotates to drive the first swing piece 11 and the second swing piece 12 to rotate and separate from the cam groove 13a, and push the first sliding sleeve 21b and the second sliding sleeve 22b, compressing the first spring 21a and the second spring 22a, and completing energy storage. When the door body touches the damper block 41, the closing speed is slowed down until the damper block 41 is retracted into the housing to compress the damper 42, and the door body is completely closed as shown in fig. 13.

When the door body is reopened, as shown in fig. 14, the door body is pressed, and the release push block 34 drives the latch hook 33 to rotate so that the clasp of the latch hook 33 is separated from the locking portion 31b of the stopper 31, and at this time, the energy of the first spring 21a and the buffer damper 42 is released. The buffer block 41 is ejected out of the housing by the buffer damper 42. The first spring 21a pushes the first sleeve rod 21 to slide, overcomes the resistance of the blocking part 31a of the blocking block 31, enables the blocking block 31 to rotate and compress the locking damper 32 and the reset spring of the locking hook 33, the first sleeve rod 21 slides along the sliding end surface of the blocking block 31 and drives the sleeve rod shifting fork 15 through the shifting rod section 21c, and at the moment, the first rotary swinging piece 11 and the second rotary swinging piece 12 push the first sliding sleeve 21b and the second sliding sleeve 22b respectively, and compress the second spring 22a and the cavity spring 24.

As shown in fig. 15, in the door opening process, when the door rotates until the cam groove 13a reaches the first swing piece 11 and the second swing piece 12, the energy of the second spring 22a and the cavity spring 24 is released, the second spring 22a pushes the second sliding sleeve 22b to slide along the second sleeve rod 22 and push the second swing piece 12 to rotate, and meanwhile, the cavity spring 24 drives the first sliding sleeve 21b to slide along the first sleeve rod 21 in the same direction and push the first swing piece 11 to rotate until one end of the first swing piece 11 and one end of the second swing piece 12 respectively sink into the cam groove 13a, so that the door is completely opened. The buffer fork 43 pushes the buffer block 41 to be restored into the housing, and compresses the buffer damper 42.

The foregoing is merely a preferred embodiment of the present invention, and it should be noted that modifications and substitutions can be made by those skilled in the art without departing from the technical principles of the present invention, and these modifications and substitutions should also be considered as being within the scope of the present invention.

Claims

1. The utility model provides a door body shutter with dynamics adjusting device, includes the casing, is equipped with drive arrangement (2) and dynamics adjusting device (5) in the casing, its characterized in that:

the driving device (2) comprises a first loop bar (21) and a second loop bar (22), the first loop bar (21) is sleeved with a first spring (21 a), and the second loop bar (22) is sleeved with a second spring (22 a);

The force adjusting device (5) comprises an adjusting screw (51), an adjusting lever (52) and an adjusting spring (53), wherein the adjusting spring (53) is arranged in the deformation direction of the second spring (22 a), one end of the adjusting lever (52) compresses the adjusting spring (53), the other end of the adjusting lever is matched with an adjusting nut (54), and the adjusting nut (54) axially moves along the adjusting screw (51).

2. The door shutter with force adjusting device according to claim 1, wherein the adjusting spring (53) is sleeved on the second sleeve rod (22), and the second sleeve rod (22) is provided with a rod body convex ring (22 c) for separating the adjusting spring (53) and the second spring (22 a).

3. The door shutter with force adjusting means according to claim 2, wherein the second loop bar (22) slides along the housing axial direction, and the adjusting lever (52) pushes the second loop bar (22) and compresses the adjusting spring (53).

4. The door shutter with the force adjusting device according to claim 1, wherein the force adjusting device (5) comprises a force indicating sheet (55) and a force indicating hole (56), the force indicating hole (56) is formed in the shell, force scales are formed at the edge of the force indicating hole (56), and the adjusting lever (52) pushes the force indicating sheet (55) to reciprocate in the force indicating hole (56).

5. The door shutter with force adjusting device according to claim 1, wherein the first sleeve rod (21) and the second sleeve rod (22) are arranged in parallel, the first sleeve rod (21) slides along the axial direction of the shell and is sleeved with a first sliding sleeve (21 b), and the second sleeve rod (22) is sleeved with a second sliding sleeve (22 b).

6. The door shutter with force adjusting device according to claim 5, wherein the housing clamps the first sliding sleeve (21 b) and the second sliding sleeve (22 b), the first sliding sleeve (21 b) and the second sliding sleeve (22 b) are in sliding fit, the first sliding sleeve and the second sliding sleeve form a sliding sleeve cavity (23), a cavity spring (24) is arranged in the sliding sleeve cavity (23), and the first sliding sleeve (21 b) and the second sliding sleeve (22 b) are linked through the cavity spring (24).

7. The door shutter with force adjusting device according to any one of claims 1 to 6, wherein the housing is provided with a door pushing device (1), the door pushing device (1) comprises a push rod (16) for pushing the door to rotate, the root of the push rod (16) is a cam (13), the cam (13) is provided with a cam groove (13 a) and a cam rod (13 b), a sleeve rod shifting fork (15) is coaxially arranged with the cam (13), and the cam (13) shifts the sleeve rod shifting fork (15) through the cam rod (13 b) so that the sleeve rod shifting fork (15) shifts the first sleeve rod (21).

8. The door shutter with force adjusting device according to claim 7, wherein the cam (13) is composed of two overlapped cam pieces, a cam clamping groove (13 c) is formed between the two cam pieces, a loop bar shifting fork (15) is arranged in the cam clamping groove (13 c), and a cam bar (13 b) is arranged in the cam clamping groove (13 c) to connect the two cam pieces.

9. The door shutter with force adjusting device according to claim 7, wherein the cam (13) of the door pushing device (1) pushes the first sliding sleeve (21 b) to compress the first spring (21 a) through the first swing member (11), and pushes the second sliding sleeve (22 b) to compress the second spring (22 a) through the second swing member (12).

10. The door shutter according to claim 9, wherein the first swing piece (11) and the second swing piece (12) are respectively composed of bearing blocks (11 a, 12 a), bearings (11 b, 12 b) and supporting seats (11 c, 12 c), one end of each bearing block (11 a, 12 a) and each supporting seat (11 c, 12 c) are connected with the shell shaft through shaft pins (14), the other two ends of each bearing block (11 a, 12 a) are respectively connected with the bearings (11 b, 12 b), bearing block grooves (11 d, 12 d) are formed in the surfaces of the bearing blocks (11 a, 12 a), supporting seat bosses (11 e, 12 e) are formed in the surfaces of the supporting seats (11 c, 12 c), the bearing block grooves (11 d, 12 d) are embedded and positioned with the supporting seat bosses (11 e, 12 e), and the two supporting seats (11 c, 12 c) are tightly adhered to each other and are in sliding fit.