CN113725747A

CN113725747A - Power distribution cabinet

Info

Publication number: CN113725747A
Application number: CN202111091026.8A
Authority: CN
Inventors: 胡全; 刘博伟; 钟洁琳; 陈鸣; 罗育辉; 周亚武; 余海腾; 刘文威; 黄晓俊
Original assignee: Guangdong Power Grid Co Ltd; Huizhou Power Supply Bureau of Guangdong Power Grid Co Ltd
Current assignee: Guangdong Power Grid Co Ltd; Huizhou Power Supply Bureau of Guangdong Power Grid Co Ltd
Priority date: 2021-09-17
Filing date: 2021-09-17
Publication date: 2021-11-30

Abstract

The invention belongs to the technical field of maintenance of power distribution cabinets and discloses a power distribution cabinet. The power distribution cabinet comprises a cabinet body, a cabinet door, two sliding frames and a mounting plate. Wherein, be provided with one side open-ended on the cabinet body and hold the chamber, the cabinet door rotates to be connected on the cabinet body, and two carriages set up in the both sides that hold in the chamber, and the mounting panel clamp that bears electrical component locates between two carriages, and the carriage includes two risers that are parallel to each other and two horizontal poles that are parallel to each other, and two horizontal pole intervals set up between two risers, and the mounting panel slides and sets up on the horizontal pole. This switch board makes maintenance personal when overhauing this switch board, and the mounting panel can shift out and hold the chamber, makes the mounting panel that bears electrical component present in the maintenance personal completely, convenient maintenance, and two carriages erect the mounting panel simultaneously, makes the mounting panel remove more firmly, and is more reasonable in structure.

Description

Power distribution cabinet

Technical Field

The invention relates to the technical field of maintenance of technical power distribution cabinets, in particular to a power distribution cabinet.

Background

The power distribution cabinet is final-stage equipment of a power distribution system and is a general name of a motor control center. The power distribution cabinet is used in the occasions with dispersed loads and less loops; the motor control center is used for occasions with concentrated loads and more loops. They distribute the power of a circuit of a higher level of power distribution equipment to nearby loads, which provide protection, monitoring and control of the loads.

Among the prior art, the most maintenance of switch board is inconvenient, and when the components and parts damage in the switch board need the maintenance, maintenance personal can only open the cabinet door and maintain it, because the inner space of switch board is compact relatively, maintenance personal can not be very comprehensive inspect, lead to easily judging inaccurately.

In order to solve the problems, the power distribution cabinet convenient to maintain is provided, and power distribution cabinet equipment comprises a power distribution cabinet body, wherein the power distribution cabinet body is a cuboid which is hollow inside and is provided with an opening at one side, and a cabinet door is hinged to the power distribution cabinet body and is rectangular; two guide rods are fixedly arranged on two sides of the inner bottom wall of the power distribution cabinet body along the length direction of the power distribution cabinet body respectively, the guide rods are cuboid, and the guide rods are arranged along the width direction of the power distribution cabinet body; slide respectively on two guide bars and be connected with two slide bars, slide bar also is the cuboid, two guide bars and two slide bar one-to-ones, slide bar along the length direction setting of guide bar, and slide bar along the length direction of guide bar slides, and the bracing piece is perpendicular with two slide bars, is provided with the mounting panel on the bracing piece. This switch board of convenient maintenance when its needs maintenance, only need open the cabinet door pull out the mounting panel can, nevertheless the mounting panel bears multiple electrical element, and weight is very big, because the mounting panel only bottom sprag when removing, self rocks the damage that causes parts such as slide bar easily.

Disclosure of Invention

The invention aims to provide a power distribution cabinet which is convenient for maintenance personnel to maintain, and a mounting plate is stable in movement, so that the overall structure is more reasonable.

In order to achieve the purpose, the invention adopts the following technical scheme:

a power distribution cabinet, comprising:

the cabinet body is provided with an accommodating cavity with one side opened;

the cabinet door is rotatably connected to the cabinet body and can open or close the opening;

the two sliding frames are arranged on two sides in the accommodating cavity, each sliding frame comprises two vertical plates which are parallel to each other and two cross rods which are parallel to each other, and the two cross rods are arranged between the two vertical plates at intervals;

the mounting panel for bear electrical component, the mounting panel presss from both sides and locates two between the carriage, and slide set up in on the horizontal pole.

Preferably, the mounting plate is configured to move in and out of the accommodating cavity.

Preferably, winding mechanism includes mount pad, reel, stay cord and coiling group, the mount pad is fixed set up in the inner wall of the cabinet body deviates from on the open-ended side, the reel rotate install in on the mount pad, the stay cord is fixed in on the mounting panel, and one end with cabinet door fixed connection, the other end twine in on the reel, coiling group is configured to the drive the reel rotates with the rolling the stay cord is located the mounting panel with the inner wall of the cabinet body deviates from part between the open-ended side.

Preferably, the cabinet further comprises a guide mechanism, the guide mechanism is arranged on the inner wall of the top of the cabinet body, and the part of the pull rope, which is positioned between the mounting plate and the cabinet door, is wound on the guide mechanism.

Preferably, the anti-skid device further comprises an anti-skid mechanism, wherein the anti-skid mechanism is configured to keep the position of the mounting plate unchanged under the condition of no external force.

Preferably, the anti-skid mechanism comprises a bar-shaped block, an elastic piece, a first rack and a second rack, the bar-shaped block is fixedly arranged on the inner wall of the bottom of the cabinet body and is provided with a through groove, one end of the elastic piece is fixed in the through groove, the other end of the elastic piece is fixedly connected to the first rack, the first rack is elastically arranged in the through groove and can slide up and down, the second rack is clamped with the first rack under the elastic action of the elastic piece, one surface of the second rack, which deviates from the first rack, is fixedly connected with the mounting plate, and when the mounting plate moves, the second rack can enable the first rack to overcome the elastic force of the elastic piece to slide downwards, so that the second rack is separated from the first rack.

Preferably, the first rack is symmetrically provided with convex parts at two sides, the through groove is symmetrically provided with concave parts at two opposite side walls, and the two convex parts are slidably arranged in the two concave parts.

Preferably, the cabinet door further comprises a positioning mechanism configured to maintain an open state of the cabinet door.

Preferably, the positioning mechanism comprises a first hinged plate, a second hinged plate, a bent plate and a locking piece, one end of the first hinged plate is fixedly connected with the cabinet door, the other end of the first hinged plate is hinged to the second hinged plate, the bent plate is fixedly arranged on the cabinet body, the bent plate is provided with a slide way, one end, deviating from the first hinged plate, of the second hinged plate is arranged in the slide way in a sliding mode, and the locking piece is configured to lock the relative position of the second hinged plate and the bent plate.

Preferably, the two sides of the mounting plate are provided with sliding blocks, and the sliding blocks are slidably sleeved on the cross rod.

The invention has the beneficial effects that:

the invention provides a power distribution cabinet which comprises a cabinet body, a cabinet door, two sliding frames and a mounting plate. Wherein, be provided with one side open-ended on the cabinet body and hold the chamber, the carriage includes two risers that are parallel to each other and two horizontal poles that are parallel to each other, and two horizontal pole intervals set up between two risers. This switch board sets up the both sides in the holding chamber through two carriages, and the mounting panel clamp is located between two carriages, and slides and set up on the horizontal pole, makes the maintenance personal when overhauing this switch board, and the mounting panel can shift out and hold the chamber, makes the mounting panel that bears electrical component present completely before the maintenance personal, convenient maintenance, and two carriages erect the mounting panel simultaneously, makes the mounting panel remove more firm, and the structure is more reasonable.

Drawings

Fig. 1 is a schematic view of an overall structure of a power distribution cabinet according to an embodiment of the present invention;

fig. 2 is a schematic diagram of an internal structure of a power distribution cabinet according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a winding mechanism of a power distribution cabinet according to an embodiment of the invention;

fig. 4 is a schematic view of an anti-skid mechanism of a power distribution cabinet according to an embodiment of the present invention;

fig. 5 is a schematic view of a positioning mechanism of a power distribution cabinet according to an embodiment of the present invention.

In the figure:

1-a cabinet body;

2-cabinet door; 21-a pull rod;

3-sliding rack; 31-a riser; 32-a cross-bar;

4-mounting a plate; 41-a slide block;

5-a winding mechanism; 51-a mounting seat; 52-a reel; 53-a pull rope; 54-a rolling group; 541-a first vertical rod; 542-a second upright; 543-a baffle plate; 544-a spiral spring;

6-a guide mechanism;

7-an anti-slip mechanism; 71-bar shaped blocks; 711-a through slot; 712-a recess; 72-a resilient member; 73-a first rack; 731-a projection; 74-a second rack;

8-a positioning mechanism; 81-a first hinge plate; 82-a second hinge plate; 83-bending plate; 831-slide way; 84-a locking member; 841-screw rod; 842-nut screw.

Detailed Description

Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar parts throughout or parts having the same or similar functions. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

In the description of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning a fixed connection, a removable connection, a mechanical connection, an electrical connection, a direct connection, an indirect connection via an intermediary, a connection between two elements, or an interaction between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the description of the present invention, unless otherwise expressly specified or limited, the first feature "on" or "under" the second feature may include the first feature and the second feature being in direct contact, or may include the first feature and the second feature being in contact not directly but with another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings.

Example one

As shown in fig. 1-2, the present invention provides a power distribution cabinet, which includes a cabinet body 1, a cabinet door 2, two sliding frames 3, and a mounting plate 4. The cabinet body 1 is a rectangular parallelepiped structure and has a cavity with an opening at one side for accommodating wires and electrical components. The cabinet door 2 is rotatably connected to the cabinet body 1 and can open or close the opening. As shown in fig. 2, the sliding rack 3 comprises two mutually parallel vertical plates 31 and two mutually parallel cross bars 32, the two cross bars 32 are arranged between the two vertical plates 31 at intervals to form a square frame structure, and the cross bars 32 are round bars, so as to facilitate processing and sliding connection with the mounting plate 4. As shown in fig. 1, two sliding frames 3 are disposed at two sides in the accommodating cavity, the mounting plate 4 is sandwiched between the two sliding frames 3 and slidably disposed on the cross bar 32, and the mounting plate 4 moves out of the accommodating cavity by sliding on the cross bar 32. It will be appreciated that the mounting plate 4 is used to carry electrical components.

This switch board sets up the both sides in the holding chamber through two carriage 3, and mounting panel 4 presss from both sides and locates between two carriage 3, and slides and set up on horizontal pole 32, makes the maintenance personal when overhauing this switch board, and mounting panel 4 can shift out and hold the chamber, makes mounting panel 4 who bears electrical component present in the front of the maintenance personal completely, convenient maintenance, and two carriage 3 erect mounting panel 4 simultaneously, makes mounting panel 4 remove more firmly, and the structure is more reasonable.

With reference to fig. 2, in order to make the mounting plate 4 and the cross bar 32 slide more conveniently and have a more reasonable structure, the two sides of the mounting plate 4 are provided with sliders 41, and the sliders 41 are sleeved on the cross bar 32. It can be understood that four sliding blocks 41 are provided, and the four sliding blocks 41 are respectively sleeved on the four cross rods 32, so that the mounting plate 4 can move more stably.

Continuing to refer to fig. 1-2, in order to make things convenient for the removal of mounting panel 4 more, this switch board still includes winding mechanism 5, and winding mechanism 5 one end sets up in holding the chamber, is located the inner wall of the cabinet body 1 and deviates from open-ended side, and the other end and cabinet door 2 fixed connection, this winding mechanism 5 can drive the automatic immigration of mounting panel 4 or shift out when maintenance personal opens cabinet door 2 and hold the chamber, make the maintenance more convenient.

Further, details of the winding mechanism 5 will now be described with reference to fig. 1 to 3. The winding mechanism 5 includes a mounting seat 51, a reel 52, a pull rope 53, and a winding set 54. Wherein, the mounting seat 51 is fixedly arranged on one side surface of the inner wall of the cabinet 1 departing from the opening, and the reel 52 is rotatably arranged on the mounting seat 51. The middle part of the pull rope 53 is fixed on the mounting plate 4, and one end of the pull rope is fixedly connected with the cabinet door 2, so that the cabinet door 2 can be pulled to move out of the accommodating cavity when being opened. The other end of the pulling rope 53 is wound on the winding wheel 52, the winding group 54 can drive the winding wheel 52 to rotate so as to wind the pulling rope 53 which is positioned between the mounting plate 4 and one side surface of the inner wall of the cabinet body 1, which is far away from the opening, so that when the cabinet door 2 needs to be closed, the winding group 54 can drive the winding wheel 52 to rotate so as to enable the pulling rope 53 to wind the winding wheel 52 and further pull the mounting plate 4 to move into the accommodating cavity.

Optionally, the winding set 54 includes a first vertical rod 541, a second vertical rod 542, and a spiral spring 544. The first vertical rod 541 is disposed on the mounting seat 51, one end of the spiral spring 544 is connected to the first vertical rod 541, the reel 52 is mounted on the mounting seat 51 and is fixedly connected to the second vertical rod 542, the spiral spring 544 is wound on the second vertical rod 542, and the spiral spring 544 can drive the second vertical rod 542 to rotate so as to drive the reel 52 to rotate. Further, in order to prevent the spiral spring 544 from coming off the second upright stanchion 542, the winding set 54 further includes a blocking plate 543, and the blocking plate 543 is disposed at an end of the first upright stanchion 541 and the end of the second upright stanchion 542 departing from the mounting seat 51 to limit the spiral spring 544.

Referring to fig. 1, in order to facilitate the fixed connection between the pull rope 53 and the cabinet door 2, the cabinet door 2 is provided with the pull rod 21, and one end of the pull rope 53, which is far away from the mounting seat 51, is fixedly disposed on the pull rod 21, so that the connection is more convenient.

Still further, with continued reference to fig. 2, in order to prevent the pulling rope 53 from rubbing against the inner wall of the cabinet 1, the switch cabinet further comprises a guiding mechanism 6. Referring now to fig. 2, the guide mechanism 6 is described, in which the guide mechanism 6 is provided with a slide groove for accommodating the pull rope 53, and the pull rope 53 is interposed in the slide groove to prevent the pull rope 53 from coming out of the guide mechanism 6. Optionally, the guiding mechanism 6 is disposed on the inner wall of the top of the cabinet 1, and a part of the pulling rope 53 between the mounting plate 4 and the cabinet door 2 is wound in the sliding groove. Further, guiding mechanism 6 includes guide shaft and two guide pulleys, and two guide pulley intervals set up in the pivot, and the pivot sets up on the inner wall at the top of the cabinet body 1, and stay cord 53 is around locating between two guide pulleys, prevents that stay cord 53 from deviating from guiding mechanism 6, makes the structure more reasonable.

With continued reference to fig. 1-2, in order to ensure that the mounting plate 4 does not move in position without being pulled by the pulling rope 53, the switch cabinet further comprises an anti-skid mechanism 7. Referring to fig. 2, the anti-slip mechanism 7 is fixedly disposed on the inner wall of the bottom of the cabinet 1, and is fixedly connected to the mounting plate 4 for supporting and limiting the mounting plate 4.

Further, with continued reference to fig. 2, in order to make the mounting plate 4 more stable in position limitation, the antiskid mechanism 7 is provided with two.

Further, the detailed structure of the antiskid mechanism 7 will now be described with reference to fig. 4. The anti-skid mechanism 7 includes a bar 71, an elastic member 72, a first rack 73, and a second rack 74. The bar-shaped block 71 is fixedly disposed on the inner wall of the bottom of the cabinet 1, and is opened with a through groove 711, one end of the elastic member 72 is fixed in the through groove 711, the other end is fixedly connected to the first rack 73, and the first rack 73 can slide up and down in the through groove 711. The second rack 74 is clamped with the first rack 73 under the elastic force of the elastic member 72, so that the first rack 73 and the second rack 74 do not move relatively. Specifically, since the second rack 74 is fixedly connected to the mounting plate 4 on the side away from the first rack 73, the first rack 73 and the second rack 74 can be engaged with each other to prevent the mounting plate 4 from moving. When opening cabinet door 2 or closing cabinet door 2, because the external force that mounting panel 4 received is great, mounting panel 4 takes place to remove under the external force effect, and then makes second rack 74 produce the effort of relative motion relative to first rack 73, and this effort overcomes the elasticity of elastic component 72 and makes first rack 73 slide downwards to make second rack 74 break away from first rack 73, make mounting panel 4 remove.

In this embodiment, the elastic member 72 is a compression spring. Further, in order to make the acting force more uniform, a plurality of elastic members 72 are provided, and the plurality of elastic members 72 are provided in the through groove 711 in parallel at intervals. Optionally, a first mounting hole for fixing the elastic member 72 is provided in the through groove 711, a second mounting hole is provided on a bottom end surface of the first rack 73 away from the second rack 74, one end of the elastic member 72 is fixed in the first mounting hole, and the other end of the elastic member 72 is fixed in the second mounting hole, so as to prevent the elastic member 72 from falling out. It is understood that the first mounting hole is in interference fit with the elastic member 72 and the second mounting hole is in interference fit with the elastic member 72.

The details of the anti-slip mechanism 7 will now be described further with continued reference to fig. 4. The first rack 73 has protruding portions 731 symmetrically provided on both sides thereof, the through groove 711 has recessed portions 712 symmetrically provided on both opposite side walls thereof, and the two protruding portions 731 are slidably provided in the two recessed portions 712 so that the first rack 73 can move up and down in the through groove 711 without coming out of the through groove 711.

Referring to fig. 1 and 5, in order to enable the cabinet door 2 to be limited after being opened, the power distribution cabinet further comprises a positioning mechanism 8, wherein the positioning mechanism 8 is arranged between the cabinet body 1 and the cabinet door 2, and can keep the cabinet door 2 in an open state.

The detailed structure of the positioning mechanism 8 will now be described with reference to fig. 5. The positioning mechanism 8 includes a first hinge plate 81, a second hinge plate 82, a bent plate 83, and a locking member 84. One end of the first hinge plate 81 is fixedly connected with the cabinet door 2, and the other end of the first hinge plate 81 is hinged with the second hinge plate 82, so that the first hinge plate 81 and the second hinge plate 82 can rotate mutually. The bent plate 83 is fixedly arranged on the cabinet body 1, the bent plate 83 is provided with a slide rail 831, one end, away from the first hinge plate 81, of the second hinge plate 82 is arranged in the slide rail 831 in a sliding mode, and when the cabinet door 2 is opened or closed, the second hinge plate 82 can slide in the slide rail 831. When the cabinet door 2 is opened to a proper position, the locking member 84 can lock the relative position of the second hinge plate 82 and the bending plate 83.

Further, the locking member 84 includes a screw 841 and a nut 842, the screw 841 is fixedly connected to the second hinge plate 82 through the slide, and when the cabinet door 2 is opened to a proper position, the nut 842 is screwed into the screw 841 to fix the bent plate 83 and the second hinge plate 82, so that the position of the cabinet door 2 is fixed.

Example two

The present embodiment provides a power distribution cabinet, which has a structure substantially the same as that of the first embodiment, and for convenience, only the difference from the first embodiment will be described.

Compared with the first embodiment, in this embodiment, adopt slide bearing to be connected between mounting panel 4 and the horizontal pole 32, be provided with four slide bearing installation departments on the mounting panel 4, four slide bearing installation departments set up with four horizontal poles 32 one-to-one, and four slide bearings are fixed to be set up in four slide bearing installation departments, and four horizontal poles 32 wear to locate in four slide bearing installation departments, make mounting panel 4's slip more smooth and easy.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A power distribution cabinet, characterized by comprising:

the cabinet body (1), the cabinet body (1) has a holding cavity with one side open;

the cabinet door (2) is rotatably connected to the cabinet body (1) and can open or close the opening;

two sliding frames (3), wherein the two sliding frames (3) are arranged on two sides in the accommodating cavity, each sliding frame (3) comprises two vertical plates (31) which are parallel to each other and two cross rods (32) which are parallel to each other, and the two cross rods (32) are arranged between the two vertical plates (31) at intervals;

the mounting plate (4) is used for bearing electric elements, and the mounting plate (4) is clamped between the two sliding frames (3) and is arranged on the cross rod (32) in a sliding mode.

2. The electrical distribution cabinet according to claim 1, further comprising a rolling mechanism (5), wherein the rolling mechanism (5) is configured to move the mounting plate (4) into or out of the accommodating cavity.

3. The switch board of claim 2, characterized in that the winding mechanism (5) comprises a mounting seat (51), a winding wheel (52), a pull rope (53) and a winding group (54), the mounting seat (51) is fixedly arranged on a side surface of the inner wall of the cabinet body (1) deviating from the opening, the winding wheel (52) is rotatably arranged on the mounting seat (51), the pull rope (53) is fixed on the mounting plate (4), one end of the pull rope is fixedly connected with the cabinet door (2), the other end of the pull rope is wound on the winding wheel (52), and the winding group (54) is configured to drive the winding wheel (52) to rotate to wind a part of the pull rope (53) between the mounting plate (4) and the side surface of the inner wall of the cabinet body (1) deviating from the opening.

4. The power distribution cabinet according to claim 3, characterized by further comprising a guide mechanism (6), wherein the guide mechanism (6) is arranged on the inner wall of the top of the cabinet body (1), and the part of the pull rope (53) between the mounting plate (4) and the cabinet door (2) is wound on the guide mechanism (6).

5. The electrical distribution cabinet according to claim 1, characterized by further comprising an anti-slip mechanism (7), wherein the anti-slip mechanism (7) is configured to keep the mounting plate (4) in a position that is not subjected to external forces.

6. The power distribution cabinet according to claim 5, wherein the anti-skid mechanism (7) comprises a bar-shaped block (71), an elastic member (72), a first rack (73) and a second rack (74), the bar-shaped block (71) is fixedly arranged on the inner wall of the bottom of the cabinet body (1) and is provided with a through groove (711), one end of the elastic member (72) is fixed in the through groove (711), the other end of the elastic member is fixedly connected to the first rack (73), the first rack (73) is elastically arranged in the through groove (711) and can slide up and down, the second rack (74) is clamped with the first rack (73) under the elastic force of the elastic member (72), and the surface of the second rack (74) departing from the first rack (73) is fixedly connected with the mounting plate (4), when the mounting plate (4) moves, the second rack (74) can slide the first rack (73) downward against the elastic force of the elastic member (72) to disengage the second rack (74) from the first rack (73).

7. A power distribution cabinet according to claim 6, wherein the first rack (73) is symmetrically provided with protruding portions (731) at two sides, the through slot (711) is symmetrically provided with recessed portions (712) at two opposite side walls, and the two protruding portions (731) are slidably arranged in the two recessed portions (712).

8. The electrical distribution cabinet according to claim 1, characterized in that it further comprises a positioning mechanism (8), said positioning mechanism (8) being configured to maintain an open state of said cabinet door (2).

9. The power distribution cabinet according to claim 8, characterized in that the positioning mechanism (8) comprises a first hinge plate (81), a second hinge plate (82), a bent plate (83) and a locking piece (84), wherein one end of the first hinge plate (81) is fixedly connected with the cabinet door (2), the other end of the first hinge plate is hinged with the second hinge plate (82), the bent plate (83) is fixedly arranged on the cabinet body (1), the bent plate (83) is provided with a slide way (831), one end of the second hinge plate (82) facing away from the first hinge plate (81) is slidably arranged in the slide way (831), and the locking piece (84) is configured to lock the relative position of the second hinge plate (82) and the bent plate (83).

10. The power distribution cabinet according to claim 1, characterized in that two sides of the mounting plate (4) are provided with sliding blocks (41), and the sliding blocks (41) are slidably sleeved on the cross rod (32).