Electric water heater inner container preloading wire positioning tool

Abstract

This invention discloses a positioning fixture for a pre-assembly line of electric water heater inner tanks, comprising a base plate mechanism, a clamping mechanism, a center synchronization mechanism, and an opening mechanism. After the empty positioning fixture is conveyed into position, the side-pushing mechanisms located on both sides of the feeding station conveyor extend, pushing the opening mechanism to release the clamping mechanism, allowing the robot to place the inner tank onto the base plate mechanism. Subsequently, the side-pushing mechanisms retract, and the clamping mechanism automatically clamps and positions the inner tank under the action of a tension spring. This invention is less affected by oxide scale and welding slag on the inner tank surface, ensuring accurate positioning, stable clamping, and high reliability during long-term production. It can also adapt to inner tanks of different diameters, effectively reducing manual intervention and lowering the error rate in automatic assembly and inspection caused by inaccurate inner tank positioning, greatly improving the assembly efficiency and product quality of the electric water heater inner tank pre-assembly line.

Description

Technical Field

[0001] This invention relates to the field of electric water heater inner tank manufacturing technology, and in particular to a positioning fixture for an electric water heater inner tank pre-assembly line. Background Technology

[0002] Electric water heaters are widely used in modern life, and due to their complex operating environment, their safety requirements are extremely high. The inner tank, as the water storage component of an electric water heater, must meet the requirements of sealing, pressure resistance, heat insulation, and rust resistance, making it the most important component. During the assembly of the inner tank, for automated workstations such as heating element flange tightening and insulation testing, the inner tank needs to be kept vertically clamped on the positioning fixture to improve the success rate of automated assembly. For manually operated workstations such as heating element flange nut pre-installation or magnesium rod tightening, which use pneumatic tools, the inner tank needs to be firmly clamped on the positioning fixture.

[0003] Currently, there are some positioning fixtures for pre-assembly lines of electric water heater inner tanks in the industry, but the positioning and clamping effect of the inner tank is not good. Especially after a period of use, the oxide scale and welding slag that fall off the surface of the inner tank will affect the clamping mechanism, causing it to jam or fail. The positioning accuracy and requirements of the inner tank cannot be guaranteed, resulting in a large difference in the overall assembly level, which directly affects the production quality of electric water heaters. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to address the shortcomings of the prior art by providing a positioning fixture for the pre-assembly line of an electric water heater inner tank. This positioning fixture is not easily affected by oxide scale and welding slag falling off the inner tank surface, and can ensure accurate positioning, stable clamping, and high reliability during long-term production. It can also adapt to inner tanks of different diameters, effectively reducing manual intervention and lowering the error rate of automatic assembly and testing caused by inaccurate inner tank positioning. This greatly improves the assembly efficiency and product quality of the electric water heater inner tank pre-assembly line.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] A positioning fixture for the pre-installation line of an electric water heater inner tank includes a base plate mechanism, a clamping mechanism, a center synchronization mechanism, and an opening mechanism.

[0007] The base plate mechanism includes the base plate and the inner liner support structure.

[0008] The base plate is slidably mounted on the water heater inner tank conveyor line, which has a water heater inner tank feeding station; both sides of the water heater inner tank conveyor line located at the water heater inner tank feeding station are equipped with a side push mechanism that can extend and retract.

[0009] The inner tank support structure is coaxially mounted on the top of the base plate to support the vertically positioned inner tank of the water heater.

[0010] The central synchronization mechanism includes a central turntable and n synchronization links; where n ≥ 3.

[0011] The central turntable is coaxially mounted on the top center of the bottom plate inside the inner liner support structure. n synchronous connecting rods are evenly distributed on the outer periphery of the central turntable, and the inner end of each synchronous connecting rod is hinged to the central turntable.

[0012] There are n clamping mechanisms, evenly distributed on the bottom and top of the outer periphery of the inner liner support structure.

[0013] Each clamping mechanism includes a centering jaw, a guide rail mounting plate, a linear guide rail, and a tension spring.

[0014] The guide rail mounting plate is mounted on top of the base plate, and the linear guide rails are laid on the lower surface of the guide rail mounting plate.

[0015] The centering jaws are slidably mounted on a linear guide rail at the bottom, and an inner tank positioning block is provided on the inner side of the top of the centering jaws. The inner tank positioning block can cooperate with the outer wall surface of the water heater's inner tank.

[0016] One side of the bottom of the centering jaw is directly or indirectly hinged to the tension spring, and the other side of the bottom of the centering jaw is directly or indirectly hinged to the outer end of the corresponding synchronous link.

[0017] The other end of the tension spring is hinged to the base plate.

[0018] There are two opening mechanisms, located on both sides of the base plate.

[0019] Each opening mechanism includes a fixed shaft and a lever; the fixed shaft is located in the middle of both sides of the base plate mechanism; the middle part of the lever is rotatably connected to the fixed shaft, and one end of the lever is hinged to the middle part of a corresponding synchronous connecting rod; the other end of the lever can contact the corresponding side push mechanism and rotate around the fixed shaft under the extension push of the side push mechanism.

[0020] The base plate mechanism includes a square base plate; the central chassis is also square in shape.

[0021] The number of synchronizing links and clamping mechanisms is n=4.

[0022] One end of each of the four synchronous connecting rods is hinged to one of the four corners of the central chassis.

[0023] The four clamping mechanisms are respectively located at the four corners of the base plate, and are all located on the two diagonals of the base plate.

[0024] The inner liner support structure includes four support blocks evenly distributed along the circumference; the four support blocks are respectively located inside the four clamping mechanisms.

[0025] The top surface of each support block is a support slope.

[0026] Each inner liner positioning block is either a V-shaped block or an arc-shaped block.

[0027] Each of the four corners of the base plate is equipped with a guide wheel, and anti-collision blocks are provided at the front and rear ends of the base plate.

[0028] Each clamping mechanism also includes two lifting blocks, a slider, and two support plates.

[0029] Two support blocks are placed at both ends of the bottom of the guide rail mounting plate and installed on the base plate, so that the bottom of the guide rail mounting plate forms a hollow cavity.

[0030] Linear guide rails are installed inside the overhead cavity.

[0031] The slider is slidably mounted on a linear guide rail, and a support plate is provided on each side of the slider.

[0032] The centering jaws are C-shaped or U-shaped, with their openings facing the central turntable; the bottoms of the centering jaws are connected to the tops of the two support plates respectively.

[0033] One of the support plates is hinged to one end of a tension spring via a spring support; the other support plate is hinged to the outer end of a synchronous connecting rod.

[0034] A bearing is mounted at the center of the central turntable via a bearing housing.

[0035] Each opening mechanism also includes an opening limit block mounted on the base plate.

[0036] The present invention has the following beneficial effects:

[0037] 1. In this invention, the linear guide rail is installed in an inverted manner, which can effectively prevent oxide scale and welding slag from falling off and accumulating on the linear guide rail. It is also less likely to cause unstable clamping of the inner liner due to the movement of the clamping mechanism, thus greatly improving the reliability of the tooling. One end of the tension spring is connected to the fixed seat fixed on the base plate mechanism, and the other end is connected to the support plate through the spring support. The tension of the tension spring itself keeps the centering jaw close to the center of the tooling, forming a centering clamping force together with the other three clamping mechanisms. The V-shaped positioning block is installed at the front end of the centering jaw, and the contact surface with the inner liner adopts a V-shaped design, which can make the positioning and clamping of the inner liner more stable and reliable.

[0038] 2. When any one of the synchronous linkages is driven by force to rotate the central turntable, it can simultaneously link the other three synchronous linkages to move synchronously, thereby enabling the clamping mechanism connected to it to clamp or release synchronously.

[0039] 3. The center of the lever can rotate around a fixed axis; the inner side of the lever is hinged to the synchronous connecting rod of the central synchronous mechanism. When the outer side of the lever is pushed, the inner side of the lever will push the synchronous connecting rod, causing the clamping mechanism connected to it to move to the outer side of the positioning fixture; at the same time, the pushed synchronous connecting rod drives the central turntable to rotate, synchronously pushing the other three synchronous connecting rods and the clamping mechanism connected to them to move to the outer side of the positioning fixture, thereby realizing the synchronous opening function.

[0040] 4. The center of the clamping mechanism, the center of the center synchronization mechanism, and the center of the base plate mechanism all coincide with the center of the inner barrel that holds the inner liner. Attached Figure Description

[0041] Figure 1 The diagram shows a structural schematic of a pre-installation positioning fixture for the inner tank of an electric water heater according to the present invention.

[0042] Figure 2 A structural diagram of the base plate mechanism in this invention is shown.

[0043] Figure 3 A structural diagram of the clamping mechanism in this invention is shown.

[0044] Figure 4 A structural diagram of the central synchronization mechanism of the present invention is shown.

[0045] Figure 5 A structural diagram of the opening mechanism in this invention is shown.

[0046] Figure 6 A three-dimensional cross-sectional view of the central synchronization mechanism of the present invention is shown.

[0047] Among them are:

[0048] 100. Base plate mechanism;

[0049] 101. Base plate; 102. Support block; 103. Positioning seat; 104. Guide wheel; 105. Anti-collision block;

[0050] 200. Clamping mechanism;

[0051] 201. Elevating block; 202. Guide rail mounting plate; 203. Linear guide rail; 204. Slider; 205. Support plate; 206. Centering gripper; 207. V-shaped positioning block; 208. Tension spring; 209. Spring support; 210. Fixing base;

[0052] 300. Central synchronization mechanism;

[0053] 301. Bearing housing; 302. Bearing; 303. Central turntable; 304. Synchronous connecting rod; 305. Hinge shaft;

[0054] 400. Open the mechanism;

[0055] 401. Fixed shaft; 402. Lever. Detailed Implementation

[0056] The present invention will now be described in further detail with reference to the accompanying drawings and specific preferred embodiments.

[0057] In the description of this invention, it should be understood that the terms "left side," "right side," "upper part," "lower part," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. "First," "second," etc., do not indicate the importance of the components, and therefore should not be construed as a limitation of this invention. The specific dimensions used in this embodiment are only for illustrating the technical solution and do not limit the scope of protection of this invention.

[0058] like Figure 1 As shown, a positioning fixture for the pre-installation line of an electric water heater inner tank includes a base plate mechanism 100, a clamping mechanism 200, a central synchronization mechanism 300, and an opening mechanism 400.

[0059] The water heater inner tank conveyor line has a water heater inner tank feeding station; both sides of the water heater inner tank conveyor line located at the water heater inner tank feeding station are equipped with a pin mechanism and a side push mechanism.

[0060] The pin mechanism can be used to limit the position of the base plate mechanism at the feeding station of the water heater inner tank.

[0061] The side-pushing mechanism can be a telescopic push rod, etc.

[0062] like Figure 2 As shown, the base plate mechanism includes a base plate 101, an inner liner support structure, a positioning seat 103, a guide wheel 104, and a crash block 105.

[0063] The base plate is slidably mounted on the water heater inner tank conveyor line and serves as the carrier for the entire positioning fixture. It is preferably square in shape.

[0064] A guide wheel is provided on each of the four corner sidewalls of the base plate. Preferably, there are four sets of guide wheels 104, which are respectively embedded in the four opposite corners of the base plate 101 to prevent the positioning fixture from getting stuck when it moves on the conveyor line.

[0065] Anti-collision blocks are preferably provided at both the front and rear ends of the base plate. Preferably, there are four anti-collision blocks 105 in total, with two sets installed at the front end of the base plate 101 in the conveying direction and the other two sets installed at the rear end of the base plate 101 in the conveying direction. They play a buffering role when the positioning fixtures are stacked, reducing the forward tilting of the water heater inner tank and preventing damage to the guide wheels.

[0066] The inner tank support structure is coaxially mounted on the top of the base plate to support the vertically positioned inner tank of the water heater.

[0067] The inner liner support structure includes four support blocks 102 evenly distributed along the circumference; preferably, the four support blocks are respectively set inside the four clamping mechanisms, fixed around the center of the positioning fixture, and the distribution diameter matches the inner liner size.

[0068] The top surface of each support block is preferably a support slope, and each inner liner positioning block is a V-shaped block or an arc-shaped block, etc. This design makes the inner liner positioning and clamping more stable and reliable.

[0069] There are four sets of positioning seats 103, which are installed on both sides of the upper surface of the base plate 101 near the side of the conveyor line. Each positioning seat is preferably provided with a pin positioning hole, which is used to fix the base plate mechanism 100 in conjunction with the pin mechanism.

[0070] like Figure 4 and Figure 6 As shown, the central synchronization mechanism includes a central turntable 303 and n synchronization links 304; wherein, n≥3, and in this embodiment, n=4 is preferred.

[0071] The central turntable is coaxially mounted at the top center of the base plate inside the inner liner support structure, and the shape of the central base plate is preferably square. The center of the central turntable preferably has a downward-convex cylindrical hollow cavity, and a bearing 302 and a bearing seat 301 are mounted on the outer wall of the cylindrical hollow cavity. The bearing seat 301 is fixed to the center of the base plate mechanism 200 and serves as the rotation reference for the central synchronization mechanism 300. The bearing 302 is mounted on the inner ring of the bearing seat 301, allowing the central turntable 303 to rotate freely via the bearing 302. Simultaneously, the central turntable 303 prevents oxide scale from falling from the outer wall of the inner liner from entering the bearing 302 and causing jamming. The four corners of the upper part of the central turntable 303 are synchronously connected to four sets of clamping mechanisms, effectively protecting the top surface of the bearing 302 and preventing foreign objects from falling into the bearing. The cylindrical hollow cavity on the central turntable 303 effectively avoids the location of the inner liner hook while allowing foreign objects falling from the inner liner to be discharged.

[0072] n (preferably n=4) synchronous connecting rods are evenly distributed on the outer periphery of the central turntable, and the inner end of each synchronous connecting rod is preferably hinged to the central turntable via a hinge pin 305. Furthermore, one end of each of the four synchronous connecting rods 304 is hinged to one of the four corners of the central turntable 303, and the other end is hinged to the corresponding clamping mechanism 200.

[0073] When any one of the synchronous links 304 is subjected to force and moves, the rotation of the central turntable 303 drives the other three synchronous links 304 to move synchronously, thereby causing the clamping mechanism connected to it to clamp or release synchronously.

[0074] There are n clamping mechanisms, evenly distributed on the bottom and top of the outer periphery of the inner liner support structure. In this embodiment, four clamping mechanisms are preferably provided, with the four clamping mechanisms respectively located at the four corners of the base plate and on the two diagonals of the base plate. They move along the diagonals of the positioning fixture and clamp towards the center simultaneously, making full use of the dimensional space in the diagonal direction of the positioning fixture, ensuring stable clamping of the inner liner while achieving a compact structure.

[0075] like Figure 3 As shown, each clamping mechanism 200 in this embodiment of the invention includes a lifting block 201, a guide rail mounting plate 202, a linear guide rail 203, a slider 204, a support plate 205, a centering jaw 206, a V-shaped positioning block 207, a tension spring 208, and a spring support 209.

[0076] The guide rail mounting plate is suspended above the base plate. Specifically, two support blocks are preferably positioned at both ends of the bottom of the guide rail mounting plate and mounted on the base plate, forming a cavity at the bottom of the guide rail mounting plate. The guide rail mounting plate and the two support blocks together form the base of the clamping mechanism 200.

[0077] The linear guide rail is installed on the lower surface of the guide rail mounting plate, that is, in the cavity. The slider is slidably mounted on the linear guide rail, and a support plate is installed on each side of the slider.

[0078] The linear guide 203 and the slider 204 are installed in an inverted manner, with the linear guide 203 located on top and fixed to the lower surface of the guide rail mounting plate 202, and the slider 204 located on the bottom and suspended upside down on the linear guide 203.

[0079] After the water heater inner tank is positioned, it is mainly used for the automatic tightening station of the heating pipe flange bolts, the insulation testing station, and the robot automatic grasping station in the subsequent pre-assembly line. Because each subsequent station has visual inspection, the posture of the water heater inner tank must be vertical and the center must not be tilted. The reverse installation of the linear guide rail of the clamping mechanism can effectively prevent the accumulation of foreign objects such as oxide scale from the outer wall of the inner tank on the linear guide rail, which would cause jamming and clamping failure, thus ensuring that the inner tank is always in a clamped and vertical state.

[0080] The centering jaws are slidably mounted on a linear guide rail at the bottom, and an inner tank positioning block is provided on the inner side of the top of the centering jaws. The inner tank positioning block can cooperate with the outer wall surface of the water heater's inner tank.

[0081] The centering gripper is preferably C-shaped or U-shaped, with its opening facing the central turntable; the bottom of the centering gripper is preferably connected to the top of the two support plates respectively, so that the centering gripper 206 is mounted above the slider 204 and can move linearly on the linear guide rail 203.

[0082] The centering gripper is hinged directly or indirectly to a tension spring on one side of its bottom. In this embodiment, the centering gripper is hinged to one end of the tension spring via a spring support 209 on the outer side of a support plate on one side of its bottom. The other end of the tension spring is hinged to a fixed seat 210 on the base plate. The tension of the tension spring 208 keeps the centering gripper 206 close to the center of the positioning fixture, forming a centering clamping force together with the other three clamping mechanisms. To ensure the inner liner remains vertical after clamping, each tension spring applies a force to the corresponding centering gripper via a linkage mechanism that is greater than the weight of the inner liner itself.

[0083] The centering gripper is hinged directly or indirectly to the outer end of a corresponding synchronizing link on the other side of its bottom. In this embodiment, the centering gripper is hinged to the outer end of the synchronizing link via the outer side of another support plate on the other side of its bottom.

[0084] There are two opening mechanisms, located on both sides of the base plate.

[0085] like Figure 5 As shown, the opening mechanism 400 in this embodiment of the invention includes a fixed shaft 401 and a lever 402, which are respectively disposed near the two conveyor lines on both sides of the positioning fixture to connect with the pin mechanism and the side push mechanism on both sides of the conveyor line. The fixed shaft 401 is mounted on the base plate mechanism 200 and is the rotation center of the lever 402; one end of the lever 402 near the central synchronization mechanism 400 is hinged to the center of the synchronization link 304, and the other end is near the side of the conveyor line and is in a free state; when the free end of the lever 402 is pushed by the side push mechanism of the station, the lever 402 rotates around the fixed shaft 401, pushing the synchronization link 304, causing the clamping mechanism 200 connected to it to move to the outside of the fixture; at the same time, the pushed synchronization link 304 drives the central turntable 303 to rotate, synchronously pushing the other three synchronization links 304 and the clamping mechanism 200 connected to them to move in the same direction, thereby making the four clamping mechanisms 200 of the positioning fixture open synchronously.

[0086] Furthermore, each opening mechanism preferably includes an opening limit block mounted on the base plate to limit the rotation angle of the lever.

[0087] The positioning fixture of this invention is self-adjustable and highly stable, not easily affected by oxide scale and welding slag on the inner tank surface. It can ensure accurate positioning and stable clamping during long-term production, and has high reliability. It can also adapt to inner tanks of different diameters, effectively reducing manual intervention and lowering the error rate of automatic assembly and testing caused by inaccurate inner tank positioning. This greatly improves the assembly efficiency and product quality of the electric water heater inner tank pre-assembly line.

[0088] A method for positioning the pre-installed wiring in the inner tank of an electric water heater includes the following steps.

[0089] Step 1, Positioning fixture conveying: The empty positioning fixture is transported to the water heater inner tank loading station via the water heater inner tank conveyor line.

[0090] Step 2, Base plate mechanism positioning: The pin mechanism limits and fixes the base plate mechanism located at the water heater inner tank feeding station.

[0091] Step 3, centering jaws open: For the positioning fixture fixed by the base plate mechanism, the side push mechanism pushes the levers of the opening mechanism on both sides of the positioning fixture. Both levers rotate around the corresponding fixed axis. The rotation of the levers drives the center synchronization mechanism to rotate in linkage, thereby causing the centering jaws in the clamping mechanism to adaptively slide outward along the linear guide rail.

[0092] Step 4, Water heater inner tank loading: With the centering jaws open, the water heater inner tank moves vertically down from directly above the central turntable and is placed on top of the support block of the inner tank support structure.

[0093] Step 5, Inner Tank Positioning: The side push mechanisms on both sides retract, and the clamping mechanisms move back to the center of the positioning fixture under the action of the corresponding tension springs, automatically centering and clamping the inner tank of the water heater.

[0094] Step 6: Pull out the latch mechanism, and repeat steps 1 to 5 to position the next water heater inner tank.

[0095] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various equivalent transformations can be made to the technical solutions of the present invention, and these equivalent transformations all fall within the protection scope of the present invention.

Claims

1. A positioning fixture for the pre-assembly line of an electric water heater inner tank, characterized in that: This includes a base plate mechanism, a clamping mechanism, a center synchronization mechanism, and an opening mechanism; The base plate mechanism includes the base plate and the inner liner support structure; The base plate is slidably mounted on the water heater inner tank conveyor line, which has a water heater inner tank feeding station. Side push mechanisms are installed on both sides of the water heater inner tank conveyor line located at the water heater inner tank feeding station. The inner tank support structure is coaxially mounted on the top of the base plate to support the vertical water heater inner tank; The central synchronization mechanism includes a central turntable and n synchronization links; where n ≥ 3; The central turntable is coaxially mounted on the top center of the bottom plate inside the inner liner support structure. n synchronous connecting rods are evenly distributed on the outer periphery of the central turntable, and the inner end of each synchronous connecting rod is hinged to the central turntable. The center of the central turntable has a downward-convex cylindrical hollow cavity, which can avoid the position of the inner liner hook while expelling foreign objects that have fallen off the inner liner; There are n clamping mechanisms, evenly distributed at the bottom and top of the outer periphery of the inner liner support structure; Each clamping mechanism includes a centering jaw, a guide rail mounting plate, a linear guide rail, and a tension spring; The guide rail mounting plate is mounted on top of the base plate, and the linear guide rail is laid on the lower surface of the guide rail mounting plate. The linear guide rail is installed in an inverted manner, which can prevent oxide scale and welding slag from falling off and accumulating on the linear guide rail, and is less likely to cause unstable clamping of the inner liner due to the movement of the clamping mechanism. The centering jaws are slidably mounted on the linear guide rail at the bottom, and an inner tank positioning block is provided on the inner side of the top of the centering jaws. The inner tank positioning block can cooperate with the outer wall surface of the water heater's inner tank. One side of the bottom of the centering jaw is directly or indirectly hinged to the tension spring, and the other side of the bottom of the centering jaw is directly or indirectly hinged to the outer end of the corresponding synchronous link. The other end of the tension spring is hinged to the base plate. The tension spring itself keeps the centering jaw close to the center of the tooling, and together with other clamping mechanisms, it forms a centering clamping force. Each tension spring applies a tension force to the corresponding centering jaw through a connecting rod that is greater than the weight of the inner liner, so that the inner liner remains vertical after clamping. There are two opening mechanisms, located on both sides of the base plate; Each opening mechanism includes a fixed shaft and a lever; the fixed shaft is located in the middle of both sides of the base plate mechanism; the middle part of the lever is rotatably connected to the fixed shaft, one end of the lever is hinged to the middle part of a corresponding synchronous connecting rod; the other end of the lever can contact the corresponding side push mechanism and rotate around the fixed shaft under the push of the side push mechanism. The center of the clamping mechanism, the center of the center synchronization mechanism, and the center of the base plate mechanism all coincide with the center of the middle barrel that holds the inner liner; The side push mechanism pushes the levers of the opening mechanism on both sides of the corresponding positioning fixture. Both levers rotate around the corresponding fixed axis. The rotation of the levers drives the central synchronization mechanism to rotate and move together, thereby causing the centering jaw in the clamping mechanism to adaptively slide outward along the linear guide rail. With the centering jaws open, the water heater inner tank moves vertically down from directly above the central turntable and is placed on the inner tank support structure. The side pushing mechanisms on both sides retract, and the clamping mechanisms move back to the center of the positioning fixture under the action of the corresponding tension springs, automatically aligning and clamping the vertical water heater inner tank.

2. The positioning fixture for the pre-installation line of the electric water heater inner tank according to claim 1, characterized in that: The base plate mechanism includes a square base plate; the central turntable is also square in shape. The number of synchronous linkages and clamping mechanisms is n=4; One end of each of the four synchronous connecting rods is hinged to one of the four corners of the central turntable; The four clamping mechanisms are respectively located at the four corners of the base plate, and are all located on the two diagonals of the base plate.

3. The positioning fixture for the pre-assembly line of the electric water heater inner tank according to claim 2, characterized in that: The inner liner support structure includes four support blocks evenly distributed along the circumference; the four support blocks are respectively located inside the four clamping mechanisms.

4. The positioning fixture for the pre-assembly line of the electric water heater inner tank according to claim 3, characterized in that: The top surface of each support block is a support slope.

5. The positioning fixture for the pre-assembly line of the electric water heater inner tank according to claim 1, characterized in that: Each inner liner positioning block is either a V-shaped block or an arc-shaped block.

6. The positioning fixture for the pre-installation line of the electric water heater inner tank according to claim 1, characterized in that: Each of the four corners of the base plate is equipped with a guide wheel, and anti-collision blocks are provided at the front and rear ends of the base plate.

7. The positioning fixture for the pre-assembly line of the electric water heater inner tank according to claim 1, characterized in that: Each clamping mechanism also includes two lifting blocks, a slider, and two support plates; Two support blocks are set at both ends of the bottom of the guide rail mounting plate and installed on the base plate, so that the bottom of the guide rail mounting plate forms a cavity. Linear guide rails are installed inside the overhead cavity; The slider is slidably mounted on a linear guide rail, and a support plate is provided on each side of the slider; The centering jaws are C-shaped or U-shaped, with their openings facing the central turntable; the bottoms of the centering jaws are connected to the tops of the two support plates respectively. One of the support plates is hinged to one end of a tension spring via a spring support; the other support plate is hinged to the outer end of a synchronous connecting rod.

8. The positioning fixture for the pre-installation line of the electric water heater inner tank according to claim 1, characterized in that: A bearing is mounted at the center of the central turntable via a bearing housing.

9. The positioning fixture for the pre-assembly line of the electric water heater inner tank according to claim 1, characterized in that: Each opening mechanism also includes an opening limit block mounted on the base plate.

Images