Multifunctional furnace body volume changing mechanism

Abstract

The utility model discloses a multifunctional furnace body volume changing mechanism, and relates to the technical field of heat treatment equipment. The furnace comprises a furnace body, a partition furnace door is arranged in the furnace body through a moving assembly, a mounting plate is arranged on the moving assembly, and a connecting assembly is further arranged between the mounting plate and the partition furnace door. The moving assembly comprises two L-shaped frames located at the front end and the rear end in the furnace body correspondingly, and threaded rods are rotationally connected into vertical supporting arms of the L-shaped frames in the vertical direction. The L-shaped frame, the movable block and the partition furnace door are mounted through the mounting plate, and the partition furnace door is driven to move in the furnace body through the L-shaped frame and the movable block, so that the volume in the furnace body is adjusted, and the problem that the volume in the furnace body is inconvenient to adjust in the prior art is solved; and meanwhile, the mounting shell and the mounting block are connected through the mounting rod, so that the mounting plate and the partition furnace door are mounted, and the problem of inconvenience in mounting and dismounting in the prior art is solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of heat treatment equipment, in particular to a multifunctional furnace body variable capacity mechanism. Background Art

[0002] Heat treatment equipment, as the name implies, is a general term for equipment that heats a workpiece in a certain medium to a suitable temperature, keeps it at this temperature for a certain period of time, and then cools it at different speeds to control its performance by changing the surface or internal structure of the workpiece. Among them, the trolley-type electric heat treatment furnace is a relatively common type of heat treatment equipment;

[0003] A trolley-type electric heat treatment furnace is a large-scale heating furnace that uses a trolley to feed large carbon steel and alloy steel parts, and can perform heat treatment processes such as heating, annealing, normalizing, quenching and tempering, surface quenching, and tempering on the parts. It has the advantages of efficient heating, precise temperature control, convenient operation and maintenance, and a wide range of applications. However, during use, since the internal space size of the trolley-type electric heat treatment furnace is fixed, it can only perform heat treatment processes on one workpiece at one temperature, which is not convenient for performing heat treatment processes on multiple workpieces at the same time or on one workpiece at different temperatures.

[0004] To this end, we provide a multifunctional furnace body variable capacity mechanism to solve the above problems. Utility Model Content

[0005] The purpose of the utility model is to provide a multifunctional furnace body variable volume mechanism, which installs an L-shaped frame and a movable block between a partition furnace door through a mounting plate, and drives the partition furnace door to move in the furnace body through the L-shaped frame and the movable block, thereby realizing the adjustment of the volume in the furnace body, solving the existing problem of inconvenience in adjusting the volume in the furnace body, and at the same time, connecting the mounting shell and the mounting block through a mounting rod, realizing the installation between the mounting plate and the partition furnace door, solving the existing problem of inconvenience in installation and disassembly.

[0006] In order to solve the above technical problems, the utility model is realized by the following technical solutions:

[0007] The utility model is a multifunctional furnace body variable capacity mechanism, comprising a furnace body, wherein a partition furnace door is arranged inside the furnace body through a moving component, a mounting plate is arranged on the moving component, and a connecting component is further arranged between the mounting plate and the partition furnace door;

[0008] The moving assembly includes two L-shaped frames respectively located at the front and rear ends of the furnace body, the interior of the vertical support arms of the L-shaped frame are connected with threaded rods for vertical rotation, a movable column is threadedly sleeved on the threaded rod, a movable block is welded on the top of the movable column, one side of the movable block is clamped on the upper side of the outer wall of one side of the partition furnace door, a first reinforcing rod is hinged on the top of the horizontal support arm of the L-shaped frame, a second reinforcing rod is movably sleeved inside the first reinforcing rod, and the top of the second reinforcing rod is hinged on the outer wall of the other side of the movable block;

[0009] Four sets of mounting plates are provided and are respectively fixedly connected to the facing surfaces of the L-shaped frame and the movable block;

[0010] The connecting assembly includes a mounting shell and a mounting block which are respectively fixedly connected to the mounting plate and the partition furnace door. The front and rear end surfaces of the mounting block are provided with mounting holes. The interior of the mounting shell is movably connected to a movable plate through a first return spring. A mounting rod is welded to the end surface of the movable plate away from the first return spring. One end of the mounting rod away from the movable plate movably penetrates the end surface of the mounting shell and is clearance-fitted in the interior of the mounting hole. One side of the movable plate movably penetrates a slide groove on the outer wall of one side of the mounting shell and is welded with a shift plate. The upper and lower parts of the outer wall of one side of the mounting shell are movably connected to L-shaped plates.

[0011] The utility model is further configured as follows: a driving rod is rotatably connected to the inside of the L-shaped frame transverse support arm, one end of the driving rod and the lower part of the outer wall of the threaded rod are sleeved with bevel gears, the bevel gears are meshed with each other, and the other end of the driving rod rotates through the outer wall of one side of the L-shaped frame transverse support arm and is fixedly connected to a hand wheel.

[0012] The utility model is further configured as follows: connecting rods are welded on the facing surfaces of the front and rear adjacent L-shaped frames, and a plurality of pulleys are fixedly connected to the bottom of the transverse support arms of the L-shaped frames at equal intervals in the transverse direction.

[0013] The utility model is further configured as follows: a positioning hole is opened above the outer wall of one side of the partition furnace door, a positioning column is matched in the internal gap of the positioning hole, and one end of the positioning column located outside the positioning hole is welded to the outer wall of one side of the movable block.

[0014] The utility model is further configured as follows: a plurality of rotating shafts are welded at equal intervals on the front and rear end surfaces of the first reinforcing rod, a rotating rod is rotatably sleeved on the rotating shaft, an end of the rotating rod away from the first reinforcing rod is movably connected to a connecting plate, and an outer wall of a side of the connecting plate away from the rotating rod is fixedly connected to the vertical support arm of the L-shaped frame.

[0015] The utility model is further configured as follows: an inner rod is provided in the inner movable sleeve of the rotating rod, and one end of the inner rod located outside the rotating rod is fixedly connected to the front and rear ends of the outer wall of one side of the connecting plate close to the rotating rod.

[0016] The utility model is further configured as follows: fixing plates are welded to the upper and lower surfaces of the mounting plate, through grooves are opened on the surfaces of the fixing plates, fixing rods are passed through the through grooves, one end of the fixing rods is respectively welded to the top and bottom sides of the mounting shell, and the other end of the fixing rods is threadedly sleeved with fastening nuts.

[0017] The utility model is further configured as follows: mounting seats are welded on the upper and lower parts of the outer wall on one side of the mounting shell, a movable rod is movably penetrated through the surface of the mounting seat, one end of the movable rod is welded to the longitudinal support arm of the L-shaped plate, the other end of the movable rod is threadedly sleeved with a limit nut, a second return spring is also sleeved on the outer side of the movable rod, and the two ends of the second return spring are respectively fixedly connected to the longitudinal support arm of the L-shaped plate and the mounting seat.

[0018] The utility model has the following beneficial effects:

[0019] The utility model provides a movable assembly and a partition furnace door, connects the L-shaped frame and the movable block with the partition furnace door through the mounting plates on the L-shaped frame and the movable block, then releases the connection between the partition furnace door and the furnace body, and applies an external force to the L-shaped frame, so that the L-shaped frame drives the partition furnace door to move inside the furnace body, thereby adjusting the internal volume of the furnace body, making it easy to adjust the volume inside the furnace body, and facilitating heat treatment processes at different temperatures for the same workpiece or different workpieces.

[0020] The utility model provides a connecting component, when the mounting shell on the mounting plate is aligned with the mounting block on the partition furnace door, an external force is applied to the L-shaped plate to separate the L-shaped plate from the shift plate. At this time, under the action of the first return spring, the movable plate applies an external force to the mounting rod. At this time, one end of the mounting rod is clearance-fitted inside the mounting hole on the front and rear end surfaces of the mounting block, thereby realizing the connection between the mounting shell and the mounting block, and the connection between the partition furnace door and the mounting plate, which is convenient for installation and disassembly of the movable component and the partition furnace door, and convenient for adjusting the volume inside the furnace body. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for describing the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 It is a schematic diagram of the overall structure of a multifunctional furnace body variable volume mechanism.

[0023] Figure 2 It is an overall front sectional view of the utility model.

[0024] Figure 3 It is a structural schematic diagram of the mobile component of the utility model.

[0025] Figure 4 It is a front cross-sectional view of the L-shaped frame of the utility model.

[0026] Figure 5 It is a structural schematic diagram of the movable block of the utility model.

[0027] Figure 6 It is a schematic diagram of the installation between the first reinforcing rod and the second reinforcing rod of the utility model.

[0028] Figure 7 It is a structural schematic diagram of the partition furnace door of the utility model.

[0029] Figure 8 It is a structural schematic diagram of the connection component of the utility model.

[0030] Fig. 9 It is a structural schematic diagram of the installation shell of the utility model.

[0031] Fig.10 It is a structural schematic diagram of the installation rod of the utility model.

[0032] Fig.11 This is a structural disassembly diagram of the L-shaped plate of the utility model.

[0033] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0034] 1-furnace body, 2-moving assembly, 201-L-shaped frame, 201a-connecting rod, 201b-pulley, 202-threaded rod, 203-driving rod, 203a-conical gear, 203b-handwheel, 204-movable block, 204a-movable column, 204b-positioning column, 205-first reinforcing rod, 205a-rotating shaft, 205b-rotating rod, 205c-inner rod, 205d-connecting plate, 206-second reinforcing rod, 3-partition furnace door, 4-installation Mounting plate, 401-fixed plate, 402-through slot, 5-connecting assembly, 501-mounting shell, 501a-fixing rod, 501b-fastening nut, 501c-slide slot, 502-mounting block, 502a-mounting hole, 503-mounting rod, 503a-first return spring, 503b-movable plate, 503c-shift plate, 504-L-shaped plate, 504a-mounting seat, 504b-movable rod, 504c-limiting nut, 504d-second return spring. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model. Example 1

[0036] See also Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 As shown, it is the first embodiment of the utility model, which provides a multifunctional furnace body 1 variable volume mechanism, including a furnace body 1, wherein a partition furnace door 3 is arranged inside the furnace body 1 through a moving assembly 2, and a mounting plate 4 is arranged on the moving assembly 2, wherein the moving assembly 2 comprises an L-shaped frame 201, a threaded rod 202, a movable block 204, a first reinforcing rod 205 and a second reinforcing rod 206, and four groups of mounting plates 4 are arranged and respectively fixedly connected to the facing surfaces of the L-shaped frame 201 and the movable block 204, and the partition furnace door 3 is driven to move inside the furnace body 1 through the movable block 204 and the L-shaped frame 201 to adjust the volume inside the furnace body 1, thereby solving the existing problem that it is inconvenient to adjust the volume inside the furnace body 1.

[0037] Specifically, two L-shaped frames 201 are provided and are respectively located at the front and rear ends of the furnace body 1. The interior of the vertical support arms of the L-shaped frame 201 is connected with a threaded rod 202 for vertical rotation. A movable column 204a is threadedly sleeved on the threaded rod 202. A movable block 204 is welded on the top of the movable column 204a. One side of the movable block 204 is clamped on the upper side of the outer wall of the partition furnace door 3. A first reinforcing rod 205 is hinged on the top of the horizontal support arm of the L-shaped frame 201. A second reinforcing rod 206 is movably sleeved inside the first reinforcing rod 205. The top of the second reinforcing rod 206 is hinged on On the outer wall on the other side of the movable block 204, the L-shaped frame 201 is used to drive the partition furnace door 3 to move inside the furnace body 1, the threaded rod 202 is used to drive the movable column 204a to move, the movable block 204 is used to fix the L-shaped frame 201 on the partition furnace door 3 at different heights, the movable column 204a is used to drive the movable block 204 to move relative to the L-shaped frame 201, the first reinforcing rod 205 and the second reinforcing rod 206 strengthen the stability of the L-shaped frame 201 and the movable block 204, so as to facilitate the movement of the partition furnace door 3.

[0038] Furthermore, the inside of the horizontal arm of the L-shaped frame 201 is rotatably connected with a driving rod 203, one end of the driving rod 203 and the lower part of the outer wall of the threaded rod 202 are sleeved with a bevel gear 203a, the bevel gears 203a are meshed with each other, and the other end of the driving rod 203 is rotatably passed through the outer wall of one side of the horizontal arm of the L-shaped frame 201 and is fixedly connected with a hand wheel 203b;

[0039] Connecting rods 201a are welded on the facing surfaces of the front and rear adjacent L-shaped frames 201, and a plurality of pulleys 201b are fixedly connected to the bottom of the transverse arms of the L-shaped frames 201 at equal intervals in the transverse direction;

[0040] A positioning hole is provided above the outer wall of one side of the partition furnace door 3, and a positioning column 204b is provided in the inner gap of the positioning hole. One end of the positioning column 204b located outside the positioning hole is welded to the outer wall of one side of the movable block 204;

[0041] A plurality of rotating shafts 205a are welded at equal intervals on the front and rear end surfaces of the first reinforcing rod 205, and a rotating rod 205b is rotatably sleeved on the rotating shaft 205a. A connecting plate 205d is movably connected to one end of the rotating rod 205b away from the first reinforcing rod 205, and an outer wall of a side of the connecting plate 205d away from the rotating rod 205b is fixedly connected to the vertical arm of the L-shaped frame 201;

[0042] An inner rod 205c is movably sleeved inside the rotating rod 205b, and one end of the inner rod 205c located outside the rotating rod 205b is fixedly connected to the front and rear ends of the outer wall of the connecting plate 205d close to the rotating rod 205b.

[0043] The operation process of this embodiment is as follows: first, the L-shaped frame 201 is moved to one side of the partition furnace door 3, and the hand wheel 203b is rotated, and the hand wheel 203b drives the driving rod 203 to rotate synchronously, and under the transmission action of the bevel gear 203a, the threaded rod 202 is rotated, and under the action of the threaded connection between the threaded rod 202 and the movable column 204a, the movable column 204a drives the movable block 204 to move relative to the L-shaped frame 201, and when the mounting plate 4 on the movable block 204 is located at the corresponding position of the partition furnace door 3, the hand wheel 203b is stopped, and the L-shaped frame 201 and the movable block 204 are connected to the partition furnace door 3 through the mounting plate 4 on the L-shaped frame 201 and the movable block 204, then the connection between the partition furnace door 3 and the furnace body 1 is released, and an external force is applied to the L-shaped frame 201, so that the L-shaped frame 201 drives the partition furnace door 3 to move inside the furnace body 1, thereby adjusting the internal volume of the furnace body 1. Example 2

[0044] See also Figure 1 , Figure 2 , Figure 8 , Fig. 9 , Fig.10 and Fig.11 As shown, it is the second embodiment of the utility model, which is based on the previous embodiment, but is different from the previous embodiment in that a connecting component 5 is also arranged between the partition furnace door 3 and the mounting plate 4, and the connecting component 5 includes a mounting shell 501, a mounting block 502, a mounting rod 503 and an L-shaped plate 504. The mounting shell 501 and the mounting block 502 are connected by the mounting rod 503, thereby realizing the connection between the partition furnace door 3 and the mounting plate 4, and solving the existing problem of inconvenience in installation and disassembly.

[0045] Specifically, the mounting shell 501 is provided with two groups and is fixedly connected to the mounting plate 4, the mounting block 502 is fixedly connected to the outer wall of one side of the partition furnace door 3, the front and rear end surfaces of the mounting block 502 are both provided with mounting holes 502a, the interior of the mounting shell 501 is movably connected with a movable plate 503b through a first return spring 503a, and a mounting rod 503 is welded on the end surface of the movable plate 503b away from the first return spring 503a, and one end of the mounting rod 503 away from the movable plate 503b movably penetrates the end surface of the mounting shell 501 and is clearance-fitted in the interior of the mounting hole 502a, and one side of the movable plate 503b movably penetrates the slide groove 501c located on the outer wall of one side of the mounting shell 501 A shift plate 503c is welded thereto, and L-shaped plates 504 are movably connected to the upper and lower parts of the outer wall of one side of the mounting shell 501. The mounting shell 501 and the mounting block 502 are used to connect the partition furnace door 3 and the mounting plate 4. The mounting rod 503 and the mounting hole 502a are used to connect the mounting shell 501 and the mounting block 502. The first return spring 503a and the movable plate 503b are used to movably mount the mounting rod 503 inside the mounting shell 501. The shift plate 503c is used to drive the mounting rod 503 to move. The L-shaped plate 504 is used to limit the movement of the shift plate 503c and thus the movement of the mounting rod 503.

[0046] Furthermore, the upper and lower surfaces of the mounting plate 4 are welded with fixing plates 401, and the surfaces of the fixing plates 401 are provided with through grooves 402, and fixing rods 501a are passed through the through grooves 402, and one end of the fixing rods 501a is respectively welded to the top and bottom sides of the mounting shell 501, and the other end of the fixing rods 501a is threadedly sleeved with fastening nuts 501b;

[0047] Mounting seats 504a are welded to the upper and lower parts of the outer wall on one side of the mounting shell 501, and movable rods 504b are movably penetrated through the surface of the mounting seats 504a. One end of the movable rod 504b is welded to the longitudinal support arm of the L-shaped plate 504, and the other end of the movable rod 504b is threadedly sleeved with a limiting nut 504c. A second return spring 504d is also sleeved on the outer side of the movable rod 504b, and both ends of the second return spring 504d are respectively fixedly connected to the longitudinal support arm of the L-shaped plate 504 and the mounting seat 504a.

[0048] The rest of the structure is the same as that of Example 1.

[0049] The operation process of this embodiment is: when the mounting shell 501 on the mounting plate 4 is aligned with the mounting block 502 on the partition furnace door 3, an external force is applied to the L-shaped plate 504, so that the L-shaped plate 504 is separated from the shift plate 503c. At this time, under the action of the first return spring 503a, the movable plate 503b applies an external force to the mounting rod 503. At this time, one end of the mounting rod 503 is loosely fitted in the mounting hole 502a on the front and rear end surfaces of the mounting block 502, thereby realizing the connection between the mounting shell 501 and the mounting block 502, and realizing the connection between the partition furnace door 3 and the mounting plate 4.

[0050] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0051] The preferred embodiments of the utility model disclosed above are only used to help explain the utility model. The preferred embodiments do not describe all the details in detail, nor do they limit the utility model to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the utility model, so that technicians in the relevant technical field can well understand and use the utility model. The utility model is limited only by the claims and their full scope and equivalents.

Claims

1. A multifunctional furnace body variable volume mechanism, comprising a furnace body (1), characterized in that: The furnace body (1) is provided with a partition furnace door (3) via a moving assembly (2), and a mounting plate (4) is provided on the moving assembly (2), and a connecting assembly (5) is further provided between the mounting plate (4) and the partition furnace door (3); The movable assembly (2) comprises two L-shaped frames (201) respectively located at the front and rear ends of the furnace body (1), and the interior of the vertical support arms of the L-shaped frames (201) are connected to threaded rods (202) in a vertically rotatable manner, a movable column (204a) is threadedly sleeved on the threaded rod (202), and a movable block (204) is welded to the top of the movable column (204a), one side of the movable block (204) is clamped on the upper side of the outer wall of the partition furnace door (3), and a first reinforcing rod (205) is hinged on the top of the horizontal support arm of the L-shaped frame (201), a second reinforcing rod (206) is movably sleeved inside the first reinforcing rod (205), and the top of the second reinforcing rod (206) is hinged on the other side of the outer wall of the movable block (204); The mounting plates (4) are provided in four groups and are respectively fixedly connected to the facing surfaces of the L-shaped frame (201) and the movable block (204); The connection assembly (5) comprises a mounting shell (501) and a mounting block (502) respectively fixedly connected to the mounting plate (4) and the partition furnace door (3), and mounting holes (502a) are provided on the front and rear end surfaces of the mounting block (502), the interior of the mounting shell (501) is movably connected to a movable plate (503b) via a first return spring (503a), and a mounting rod (503) is welded to the end surface of the movable plate (503b) away from the first return spring (503a), one end of the mounting rod (503) away from the movable plate (503b) movably penetrates the end surface of the mounting shell (501) and is clearance-fitted in the interior of the mounting hole (502a), and one side of the movable plate (503b) movably penetrates a slide groove (501c) located on the outer wall of one side of the mounting shell (501) and is welded to a shift plate (503c), and the upper and lower parts of the outer wall of one side of the mounting shell (501) are movably connected to an L-shaped plate (504).

2. A multifunctional furnace volume-changing mechanism according to claim 1, characterized in that: The inside of the transverse support arm of the L-shaped frame (201) is rotatably connected to a driving rod (203), and one end of the driving rod (203) and the lower part of the outer wall of the threaded rod (202) are sleeved with a bevel gear (203a), the bevel gears (203a) are meshed with each other, and the other end of the driving rod (203) rotatably passes through the outer wall of one side of the transverse support arm of the L-shaped frame (201) and is fixedly connected to a hand wheel (203b).

3. A multifunctional furnace volume-changing mechanism according to claim 2, characterized in that: Connecting rods (201a) are welded on the facing surfaces of the front and rear adjacent L-shaped frames (201), and a plurality of pulleys (201b) are fixedly connected to the bottom of the transverse support arms of the L-shaped frames (201) at equal intervals in the transverse direction.

4. The multifunctional furnace volume-changing mechanism according to claim 1, characterized in that: A positioning hole is provided above the outer wall of one side of the partition furnace door (3), and a positioning column (204b) is provided in the internal gap of the positioning hole. One end of the positioning column (204b) located outside the positioning hole is welded to the outer wall of one side of the movable block (204).

5. The multifunctional furnace volume-changing mechanism according to claim 1, characterized in that: A plurality of rotating shafts (205a) are welded at equal intervals on the front and rear end surfaces of the first reinforcing rod (205), and a rotating rod (205b) is rotatably sleeved on the rotating shaft (205a), and an end of the rotating rod (205b) away from the first reinforcing rod (205) is movably connected to a connecting plate (205d), and an outer wall of a side of the connecting plate (205d) away from the rotating rod (205b) is fixedly connected to a vertical support arm of the L-shaped frame (201).

6. The multifunctional furnace volume-changing mechanism according to claim 5, characterized in that: The inner movable sleeve of the rotating rod (205b) is provided with an inner rod (205c), and one end of the inner rod (205c) located outside the rotating rod (205b) is respectively fixedly connected to the front and rear ends of the outer wall of one side of the connecting plate (205d) close to the rotating rod (205b).

7. The multifunctional furnace volume-changing mechanism according to claim 1, characterized in that: The upper and lower surfaces of the mounting plate (4) are both welded with fixing plates (401), and the surfaces of the fixing plates (401) are both provided with through grooves (402), the interior of the through grooves (402) is penetrated by fixing rods (501a), and one end of the fixing rods (501a) is respectively welded to the top and bottom sides of the mounting shell (501), and the other end of the fixing rods (501a) is threadedly sleeved with fixing nuts (501b).

8. The multifunctional furnace volume-changing mechanism according to claim 1, characterized in that: Mounting seats (504a) are welded to the upper and lower parts of the outer wall of one side of the mounting shell (501), and a movable rod (504b) is movably penetrated through the surface of the mounting seat (504a), one end of the movable rod (504b) is welded to the longitudinal support arm of the L-shaped plate (504), and the other end of the movable rod (504b) is threadedly sleeved with a limit nut (504c), and a second return spring (504d) is also sleeved on the outer side of the movable rod (504b), and the two ends of the second return spring (504d) are respectively fixedly connected to the longitudinal support arm of the L-shaped plate (504) and the mounting seat (504a).

Images