Gear powder metallurgy sintering device

Abstract

The application discloses a gear powder metallurgy sintering device, and relates to the technical field of powder metallurgy, which comprises a base, two groups of supports are rotationally connected to the base, disc-shaped racks for bearing sintered gears are fixed to the top of the two groups of supports, the disc-shaped racks are provided with positioning rods for positioning the gears in a circle, first counterweights and second counterweights are respectively connected to the bottom of the two groups of supports, the first counterweight is a cavity, and a plurality of groups of shape memory alloy strips are arranged in the first counterweight. The gear powder metallurgy sintering device is provided with two groups of supports, counterweights and disc-shaped racks are arranged at the end of the supports, and shape memory alloy strips are arranged in the first counterweight. The shape memory alloy strips can change the position of the center of mass of the first counterweight with temperature change, so that the sintered gears can automatically realize turning over during the sintering process, the two surfaces of the gears can be sintered in a completely empty state, and temperature difference caused by shielding is avoided, so that the sintering quality is affected.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of powder metallurgy, in particular to a gear powder metallurgy sintering device. BACKGROUND

[0002] Powder metallurgy is a metal material preparation technology, which mixes metal or alloy raw material powder according to a certain proportion, presses into shape, and goes through process steps such as sintering or heat treatment to prepare metal products with certain shape and performance.

[0003] There are two ways of powder metallurgy sintering, one is sealed sintering, i.e. static atmosphere sintering, and the other is non-sealed sintering, i.e. open atmosphere sintering. Both have advantages and disadvantages. The atmosphere environment is good when sealed, and the sintering is more stable, but the single sintering cycle is long. The non-sealed type is continuous sintering, and the cycle is short, but the open environment is not as good as the sealed type. Because the efficiency of open sintering is higher, it is more widely used.

[0004] No matter which way of sintering, the gear products to be sintered are placed in a tooling tray or directly placed on a mesh belt during the sintering process. However, no matter which way, the gear has a certain position that is blocked, i.e. in contact with other parts. If it is the mutual contact between gears, or it is in contact with the tooling tray or mesh belt, after contact, it causes a certain temperature difference between the position and the unblocked area of the sintered gear. Moreover, it may also cause the lubricant and forming agent in the gap of the product to be unable to discharge after sintering, thereby affecting the sintering quality. Therefore, we propose a gear powder metallurgy sintering device. SUMMARY

[0005] The purpose of the present application is to provide a gear powder metallurgy sintering device to solve the problems raised in the background art.

[0006] In order to achieve the above object, the present application provides the following technical scheme: a gear powder metallurgy sintering device, comprising a base, two groups of supports are rotatably connected to the base, the top of the two groups of supports is fixed with disc-shaped racks for bearing sintered gears, the two groups of disc-shaped racks can coincide with each other in axis when moving towards each other, the disc-shaped racks are provided with positioning rods for positioning the circumferences of the gears, the positioning rods are used for positioning and supporting the inner circumferences or outer circumferences of the sintered gears, the bottom of the two groups of supports is further connected with a first counterweight and a second counterweight respectively, in the initial balance state, the two disc-shaped racks are located on both sides of the plane formed by the rotation axis of the support and the vertical direction, and the disc-shaped rack axis is not in a horizontal state, the first counterweight is a cavity, and the first counterweight is provided with a heat insulation material, the first counterweight is provided with two groups of shape memory alloy strips, the transformation temperature of the two groups of shape memory alloy strips is different, and the shape memory alloy strip with a lower transformation temperature changes the center of mass of the first counterweight in the direction away from the support and moves the corresponding disc-shaped rack towards the other disc-shaped rack, while the other group of shape memory alloy strips moves the corresponding disc-shaped rack in the opposite direction away from the other disc-shaped rack.

[0007] Preferably, the disc-shaped rack is provided with a through groove extending in the axial direction of the disc-shaped rack, the positioning rod is slidably arranged in the through groove, a plurality of clamping grooves are arranged on the positioning rod, and a protruding columnar body is arranged on the disc-shaped rack and corresponds to the clamping grooves, the positioning rod is fixed by cooperation of the clamping grooves and the clamping grooves, and the through grooves on the two groups of disc-shaped racks are staggered.

[0008] Preferably, the through groove is provided with a plurality of groups, and each group is arranged on a different circumference.

[0009] Preferably, the first counterweight and the second counterweight are detachably arranged on the support, and can be slidably adjusted and locked in the extension direction of the corresponding support.

[0010] Preferably, the base is adjustable in height.

[0011] Preferably, the first counterweight and the second counterweight are modularly arranged and can be connected to each other.

[0012] Preferably, the positioning end of the positioning rod is provided with a guide section.

[0013] Preferably, the base is divided into a plurality of segments in the axial direction of the rotation axis of the support, and the segments are hingedly connected.

[0014] Compared with the prior art, the present application has the following beneficial effects:

[0015] The present application sets two groups of supports, sets counterweight and disc-shaped frame at the end of the support, and sets shape memory alloy strip in the first counterweight, the shape memory alloy strip can change the position of the centroid of the first counterweight with temperature change, so that the sintering gear automatically realizes turning over in the sintering process, makes the gear both sides have completely empty state sintering, avoids forming temperature difference due to shielding, and influences sintering quality;

[0016] The positioning rod can be axially adjusted and radially selected, and can be suitable for positioning of gears with different inner and outer diameters, and the overall applicability of the equipment is improved. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of the present application;

[0018] Figure 2 It is a schematic diagram of the structure of the sintering gear of the present application;

[0019] Figure 3 It is a schematic diagram of the state structure of the sintering gear transfer of the present application;

[0020] Figure 4 It is a schematic diagram of the structure of a single disc-shaped frame;

[0021] Figure 5 It is a schematic diagram of the structure of a single disc-shaped frame;

[0022] Figure 6 It is a schematic diagram of the structure of a single disc-shaped frame;

[0023] Figure 7 It is Figure 6 It is an enlarged schematic diagram of the structure of the A area;

[0024] Figure 8 It is a schematic diagram of the structure of the A area;

[0025] Figure 9 It is a schematic diagram of the structure of the A area;

[0026] Figure 10 It is an embodiment of the distribution state of the shape memory alloy strip;

[0027] Figure 11 It is another embodiment of the distribution state of the shape memory alloy strip;

[0028] Figure 12 It is another embodiment of the distribution state of the shape memory alloy strip;

[0029] Figure 13 It is a schematic diagram of the distribution structure of the inoculation state of the positioning rod.

[0030] In the figure: 1-base; 2-bracket; 3-disc-shaped frame; 4-positioning rod; 5-first counterweight; 6-second counterweight; 7-shape memory alloy strip; 8-columnar body; 9-clamp; 10-guiding section; 301-through slot; 401-clamping slot. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0032] Referring to Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 9 , Figure 10 , Figure 11 , Figure 12 and Figure 13 , the present application provides a technical solution: a gear powder metallurgy sintering device, comprising a base 1, the base 1 is directly placed in a sintering furnace cavity or on a mesh belt of a sintering furnace, depending on the specific type of sintering furnace used, two groups of brackets 2 on the base 1 are cross-shaped, and the two ends are respectively connected to disc-shaped frames 3 and counterweights, the difference between the two groups of brackets is that the counterweights connected to the lower ends of the two groups of brackets are different, one group is a first counterweight 5, the first counterweight 5 is a hollow structure, and the first counterweight 5 includes at least two layers, one layer is a heat insulation material, and the other layer is a counterweight, because the sintering temperature is generally above 1000℃, the melting point of the heat insulation material should be higher than the sintering temperature, such as silicon carbide material which can maintain stability above 2000℃, or high-temperature-resistant glass above 1500℃, on the other hand, the heat insulation material is not necessarily a material layer, but also can be a heat insulation coating, inorganic series of high-temperature-resistant coatings can withstand at least 1000 degrees Celsius high temperature, the main function of heat insulation is to reduce the temperature in the cavity of the first counterweight 5, the cavity of the first counterweight 5 is provided with two groups of shape memory alloy strips 7, i.e. memory metal, the transformation temperature of the two groups of memory metals is different, i.e. the temperature difference has a deformation threshold, the function of the second counterweight 6 is only counterweight;

[0033] The disc-shaped frame 3 is preferably a circular disc hollow structure, used to support the gear to be sintered, when it is not in the state of entering the furnace, and the gear to be sintered is not placed on the disc-shaped frame 3, the disc-shaped frame 3 and the counterweight are like Figure 1As shown in the state, the two disc-shaped racks 3 are respectively located on both sides of the axis of the rotating shaft of the two supports 2 and are respectively inclined to the left and right sides, at this time, the first counterweight 5 and the second counterweight 6 keep the two disc-shaped racks 3 in a balanced state, the disc-shaped rack 3 corresponding to the first counterweight 5 is used to initially place the sintering gear, after placing the sintering gear, if Figure 2 the state, Figure 1 the disc-shaped rack 3 on the right side of the state shown is inclined to the right side, that is, the first counterweight 5 is moved upward, during the sintering process, the temperature of the heat insulation material pattern is mostly high, but the temperature in the inner cavity of the first counterweight 5 is still slowly rising, when the temperature in the inner cavity of the first counterweight 5 reaches the temperature of the shape memory alloy strip 7 of the group with low temperature, the shape memory alloy strip 7 starts to deform, the deformation makes the overall center of mass of the first counterweight 5 move to the left, so that the first counterweight 5 moves downward, that is, the disc-shaped rack 3 corresponding to the first counterweight 5 moves (rotates around the rotating shaft) toward the other disc-shaped rack 3, reaches Figure 3 the state, because the two disc-shaped racks 3 are inclined to the left, the gear on the first counterweight 5 slides to the other disc-shaped rack 3 due to gravity, in this state, the overall center of mass of the disc-shaped rack 3 corresponding to the first counterweight 5 is still on the right side (that is, the bottom of the disc-shaped rack 3 can be counterweighted to make the center of mass on the right side), to avoid that the disc-shaped rack 3 cannot be reset, the upper end of the support 2 connected with the first counterweight 5 has a corner or the connection with the disc-shaped rack 3 is at an angle, so as to facilitate the disc-shaped rack 3 to return to the initial state as Figure 3 shown in the state, the first counterweight 5 will not run to the right side, the left and right sides in the above corresponding figure are the left and right sides of the plane formed by the rotating shaft and the vertical direction;

[0034] Because of the transfer of the sintering gear, in order to make the disc-shaped rack 3 corresponding to the first counterweight 5 move to the right side and return to the initial state, it is necessary to change the center of mass position of the first counterweight 5, therefore, as the sintering continues, the temperature in the inner cavity of the first counterweight 5 continues to rise, when the temperature in the inner cavity of the first counterweight 5 reaches the deformation temperature of the shape memory alloy strip 7 of the group with high temperature, the shape memory alloy strip 7 makes the center of mass of the first counterweight 5 move to the right, so that the corresponding disc-shaped rack 3 returns to the initial state, the initial state is convenient for placing the sintering gear, preferably, the deformation initial time of the first group of shape memory alloy strips 7 is the middle section of the total sintering time, so as to facilitate the sintering gears to have the same sintering time on both sides after turning over;

[0035] as shown in Figure 9 , the shape memory alloy strips 7 can be arranged in multiple layers in the first counterweight 5, and the specific distribution can be as shown in Figure 10 , each shape memory alloy strip 7 can be bent and deformed to the left or to the right to change the center of mass, as another embodiment, the shape memory alloy strips 7 can also be as shown in Figure 11 the state, the shape memory alloy strips 7 contract along the length direction, that is, the length direction is S-shaped, deformed and contracted, as still another embodiment, the shape memory alloy strips 7 can also be as shown in Figure 12 the curved shape;

[0036] Positioning rod 4 is used for positioning sintered gear, so as to be stably placed on disc-shaped frame 3, as shown in Figure 13 Figure, positioning rod 4 can have various ways when positioning inner circle of gear, such as using Figure 13 a point position, only single positioning rod 4 can realize positioning, or using two positioning rods 4, the position of which is between a-b and b-c, including a and c points, and in order to balance the force of positioning rod 4, two positioning rods 4 are on the same horizontal line, and more than two positioning rods 4 can be used, which are uniformly distributed along the circumference, when positioning outer circle of gear, at least two positioning rods 4 are needed, that is, d and e points of 13, the two points are preferably on the same horizontal line, and the two points are not coincident and are located below the horizontal diameter line of gear, preferably, the angle between the diameter of gear at d and e points and the vertical direction is 30°-60°, such as 30°, 40°, 45°, 50° and 60°.

[0037] Referring to Figure 4 , Figure 5 , Figure 6 , Figure 7 and Figure 8 , as an embodiment of positioning rod 4, a set of three positioning rods 4 are arranged, which are uniformly distributed along the circumference and are arranged as inner positioning, the three positioning rods 4 are fixed by connecting rods, three integrations are convenient for unified adjustment, corresponding through slots 301 are opened on disc-shaped frame 3 corresponding to positioning rod 4, positioning rod 4 can slide in the axial direction in through slot 301, the axial movement of positioning rod 4 is used for adjusting the length of positioning end, so as to correspondingly adjust according to the thickness of sintered gear, the non-positioning end of positioning rod 4 is provided with a plurality of clamping grooves 401, and a columnar body 8 is arranged on disc-shaped frame 3, and a clamping groove 401 is also arranged on columnar body 8, each clamping groove 401 is located on the same circumference, and a C-shaped clamp is limited positioning rod 4 through clamping groove 401;

[0038] Two disc-shaped frames 3 need to be close to each other to transfer sintered gear during sintering, if positioning rods 4 interfere with each other, the movement of disc-shaped frame 3 will cause instability during the movement of gear, therefore, the positions of positioning rods 4 on different disc-shaped frames 3 are staggered, as shown in Figure 8 Positioning rod 4 has overlapping part in the axial direction, even if support 2 shakes, it can still stably butt joint and transfer sintered gear to turn over.

[0039] Further, on the basis of the last embodiment, a plurality of through slots 301 are arranged, each of which is located on different circumferential lines, so as to adapt to gears with different inner diameters.

[0040] In order to further improve the adaptability of the device, for a variety of gears, the first counterweight 5 and the second counterweight 6 are arranged to be detachable and adjustable in position, for example, by opening threaded holes on the counterweights, and by locking the counterweights to the support 2 through bolts to fix the position, or by connecting the lower end of the support 2 to the counterweights through threaded connection, the counterweights can be adjusted in position to adapt to different mass of sintered gears.

[0041] In the adjustable state of the counterweights, after adapting to different sintered gears, the downward range of the counterweights is larger, so the base 1 can adjust the height to adapt to

[0042] The counterweights are arranged in a modular manner, and are connected to each other through a similar building block or other connection manner, so as to reduce or increase the weight, and further improve the mass range of the adapted sintered gears.

[0043] Referring to Figure 6 and Figure 8 The guide section 10 is inclined to the axis, and if it is externally positioned, it should be inclined outwardly away from the axis of the disc-shaped frame 3, and the guide section 10 is used to facilitate quick placement of the gear and guide.

[0044] The bottom of the base 1 is arranged in several sections, and each section is hinged, and the maximum expansion angle is in the expanded planar state, and this mode is adapted to be mounted on the mesh belt, and can be rotated with the arc-shaped position of the mesh belt at the conveying end, and can also realize automatic unloading, and the gear is separated from the disc-shaped frame 3 under the action of gravity.

[0045] It should be noted that in this document, relational terms such as first and second and the like can be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0046] Although embodiments of the present application have been shown and described, it is to be understood that various modifications, substitutions, replacements and changes can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A gear powder metallurgy sintering device comprising a base (1), characterized in that: The base (1) is rotatably connected with two groups of supports (2), the top of the two groups of supports (2) is fixed with disc-shaped racks (3) for bearing sintered gears, the two disc-shaped racks (3) can coincide in axis when moving towards each other, the disc-shaped rack (3) is provided with a positioning rod (4) for positioning the circumferential edge of the sintered gear, the positioning rod (4) is used for positioning and supporting the inner circumferential or outer circumferential edge of the sintered gear, the bottom of the two groups of supports (2) is further connected with a first counterweight (5) and a second counterweight (6) respectively, in the initial balanced state, the two disc-shaped racks (3) are located on both sides of the plane formed by the rotation axis of the support (2) and the vertical direction, and the disc-shaped rack (3) axis is not in a horizontal state, the first counterweight (5) is a cavity, and the first counterweight (5) is provided with a heat insulation material, the first counterweight (5) is provided with two groups and a plurality of shape memory alloy strips (7) in each group, the two groups of shape memory alloy strips (7) have different transformation temperatures, and the shape memory alloy strips (7) with a lower transformation temperature change the center of mass of the first counterweight (5) away from the direction of the support (2), and make the corresponding disc-shaped rack (3) move towards the other disc-shaped rack (3), while the other group of shape memory alloy strips (7) moves in the opposite direction to make the corresponding disc-shaped rack (3) move away from the other disc-shaped rack (3); The disc-shaped rack (3) is provided with a through groove (301) extending along the axial direction of the disc-shaped rack (3), and the positioning rod (4) is slidably arranged in the through groove (301), a plurality of clamping grooves (401) are formed in the positioning rod (4), and the disc-shaped rack (3) is also provided with a protruding columnar body (8) and a clamping groove (401) arranged correspondingly, the positioning rod (4) is fixed by cooperation of the clamping groove (401) and the clamping hoop (9), and the through grooves (301) on the two disc-shaped racks (3) are staggered.

2. A powder metallurgy sintering apparatus for gears according to claim 1, characterized in that: The through groove (301) is provided with a plurality of groups, and each group is arranged on different circumferential lines.

3. A powder metallurgy sintering device for gears according to claim 1 or 2, characterized in that: The first counterweight (5) and the second counterweight (6) are detachably arranged on the support (2), and can be slidably adjusted and locked in the extension direction of the corresponding support (2).

4. A powder metallurgy sintering apparatus for gears according to claim 3, wherein: The base (1) can be adjusted in height.

5. A powder metallurgy sintering apparatus for gears according to claim 3, wherein: The first counterweight (5) and the second counterweight (6) are modularly arranged and can be connected to each other.

6. The apparatus for powder metallurgy sintering of gears as claimed in claim 1, wherein: The positioning end of the positioning rod (4) is provided with a guide section (10).

7. The apparatus of claim 1 wherein: The base (1) is divided into a plurality of segments along the axial direction of the rotation axis of the support (2), and the segments are hingedly connected.

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