Positioning structure adopted for heat treatment of bucket lip of integrally-manufactured large bucket
By setting limit fixing blocks on the arc vertex, the middle and side walls of the arc vertex of the large bucket lip, the problem of thermal stress deformation during the heat treatment of the large bucket lip is solved, and the dimensional accuracy and mechanical performance of the casting are guaranteed.
Patent Information
- Application Number
- CN202421712533.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-19
- Publication Date
- 2025-07-29
- Estimated Expiration
- 2034-07-19
AI Technical Summary
Large bucket lips are prone to deform during overall casting and heat treatment, making it difficult to ensure dimensional accuracy and mechanical properties.
Limit fixed blocks are provided at the arc apex, the middle part of the arc on both sides of the vertex casting, and the side walls of the arc on both sides of the vertex, so as to control the thermal stress deformation during the heat treatment through mechanical means.
Effectively control deformation during heat treatment to ensure the dimensional accuracy and mechanical properties of the castings.
Smart Images
Figure CN223163449U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of mechanical manufacturing, and particularly relates to a positioning structure adopted for heat treatment of an integrally manufactured large bucket lip. Background Technique
[0002] The bucket is one of the important components of a forklift. The bucket lip is the part of the bucket that directly contacts the external materials and is subjected to the greatest friction, impact, and bending stress. Its structural stability, overall manufacturing strength, dimensional accuracy, etc. directly affect the welding quality, assembly quality, service life, etc. of the bucket lip and the bucket body.
[0003] Generally, the bucket lip and the front arm of small and medium-sized buckets are integrally cast. However, for large buckets generally exceeding 30 cubic meters, the bucket lip is cast in a split form. And due to the large size of the bucket lip, with a nominal size greater than 3.5 m, and the structural form that is prone to deformation and dimensional accuracy, it is necessary to adopt the method of casting three parts and then combining them into a complete bucket lip to ensure the strength and welding and installation accuracy of the bucket lip.
[0004] According to the original process production, the bucket lip casting with a "U" - shaped structure needs to be cast in three parts: left, right, and bottom. Cast in three parts, solution treatment is carried out. After cleaning, it is necessary to machine the welding groove at the butting part, and then weld and form after combination. Producing according to this process has a high labor intensity and low efficiency in the casting process. Especially after solution treatment, carbide precipitates at the welded joint of the high - manganese steel casting at high temperature, causing the welded joint to become brittle and prone to cracking, affecting the service life. At the same time, the welding workload is increased and the production efficiency is reduced.
[0005] For the form of integral casting of large bucket lips, due to the difference in shrinkage rates of various parts of the large bucket lip during casting and solution treatment, deformation is extremely likely to occur, and it is very difficult to ensure the dimensional accuracy requirements and mechanical property requirements of the large bucket lip.
[0006] During the integral pouring process of the large bucket lip, there are two deformation - prone stages that need to be particularly controlled. One stage is at the end of pouring. Due to different shrinkage rates of various parts, the side vertical walls are severely deformed, and this deformation can be regulated through the casting process. The second deformation - prone stage is the heat treatment stage. During the heat treatment process, the change in thermal stress is very likely to cause large deformation of the casting, and it is impossible to ensure the dimensional accuracy of the final casting. Summary of the Utility Model
[0007] The purpose of the utility model is to provide a positioning structure adopted for heat treatment of an integrally manufactured large bucket lip. During the heat treatment process of the integral casting of the bucket lip, through mechanical means, limit fixing blocks are respectively arranged at the arc vertex of the bucket lip, the middle of the arc on both sides of the vertex, and the side wall of the bucket lip, which can effectively control the deformation caused by the change in thermal stress during the heat treatment process, and finally ensure the dimensional accuracy of the casting.
[0008] To achieve the above object, the utility model adopts the following technical solutions:
[0009] A positioning structure used for heat treatment of an integrally manufactured large bucket lip includes an integral bucket lip casting, a drag plate, and a number of limit fixing blocks. One side of the flange large plane of the integral bucket lip casting is placed on the drag plate. The number of limit fixing blocks are respectively arranged at the arc vertex of the integral bucket lip casting, the middle parts of the arcs on both sides of the vertex, and the position of the bucket lip side wall. The limit fixing blocks at the arc vertex of the integral bucket lip casting and the middle parts of the arcs on both sides of the vertex are arranged on both sides of the arc wall of the integral bucket lip casting, and the limit fixing block on the bucket lip side wall is arranged on the inner wall of the bucket lip. The number of said limit fixing blocks are all fixedly connected with the drag plate.
[0010] The integral bucket lip casting is a bucket lip casting with a volume of more than 55 cubic meters or a single weight exceeding 8 tons.
[0011] The limit fixing block is a metal block.
[0012] The cross-section of the limit fixing block is square, and the height is 80 - 120 mm; the cross-sectional size is (120 - 150) mm × (50 - 80) mm.
[0013] The bucket lip is a bucket lip with a volume of 55 cubic meters or a single weight exceeding 8 tons.
[0014] Compared with the prior art, the beneficial effect of the utility model is:
[0015] A positioning structure used for heat treatment of an integrally manufactured large bucket lip, during the heat treatment process of the integral bucket lip casting, through mechanical means, limit fixing blocks are respectively arranged at the arc vertex of the bucket lip, the middle parts of the arcs on both sides of the vertex, and the bucket lip side wall, which can effectively control the deformation caused by the change of thermal stress during the heat treatment process, and finally ensure the dimensional accuracy of the casting. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 is the front view of the large bucket lip part drawing.
[0017] Figure 2 is the side view of the large bucket lip part drawing.
[0018] Figure 3 is the structural schematic of the limit component during the heat treatment of the casting of the utility model (the part view is Figure 1 the bottom view).
[0019] In the figure: 1 - cylindrical external chill, 2 - limit fixing block, 3 - integral bucket lip casting, 4 - drag plate. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0020] The following further describes the embodiments of the utility model with reference to the drawings:
[0021] See Figures 1 - 3 , a positioning structure adopted for heat treatment of an integrally manufactured large bucket lip, comprising an integral bucket lip casting 3, a drag plate 4, and a plurality of limit fixing blocks 2. One side of the flange large plane ( Figure 1 the B surface in
[0022] ) of the integral bucket lip casting 3 is placed on the drag plate 4. The plurality of limit fixing blocks 2 are respectively arranged at the arc vertices of the integral bucket lip casting 3, the middle parts of the arcs on both sides of the vertices, and the side walls of the bucket lip. The limit fixing blocks 2 at the arc vertices and the middle parts of the arcs on both sides of the vertices of the integral bucket lip casting 3 are arranged on both sides of the arc wall of the integral bucket lip casting 3, and the limit fixing blocks 2 on the side walls of the bucket lip are arranged on the inner wall of the bucket lip. The plurality of limit fixing blocks 2 are all fixedly connected to the drag plate 4.
[0023] The limit fixing block 2 is a metal block.
[0024] The cross-section of the limit fixing block 2 is square, and the height is 80 - 120 mm; the cross-sectional dimension is (120 - 150) mm × (50 - 80) mm.
[0025] Example:
[0026] In the example, the bucket lip is a 55-cubic-meter bucket lip, and the chemical composition of the bucket lip casting is as follows by mass percentage: C 0.80%, Si 0.4%, Mn 13%, P 0.02%, S 0.02%, Mo 1%, and the rest is Fe and unavoidable impurities.
[0027] The casting method for integrally manufacturing a large bucket lip is as follows:
[0028] 1) Taking the flange large plane B of the bucket lip as the parting surface (see Figure 1 ), all the castings are modeled in the lower box, and vertical modeling casting is adopted. The upper box is a flat cover; a heating riser sleeve is used for the upper box riser to improve the feeding efficiency.
[0029] Adopting vertical modeling casting, the shrinkage rate at the bottom of the bucket lip is 25% - 28% and the shrinkage rate at the top is 15% - 20% through gravity feeding.
[0030] The inner arc surface of the bucket lip adopts an integral sand core from top to bottom. Horizontally, it is formed by dividing into multiple blocks, preferably divided into 6 blocks.
[0031] 2) The gating system adopts two layers of inner gates, and the number of each layer is more than 6.
[0032] 3) Adopt low-temperature and fast pouring, the pouring temperature is 1460 °C, and the pouring time is 150 s.
[0033] 4) See Figure 1, chill measures are placed at the rounded corners of each part, and chromite sand or shaped external chillers are placed; external chillers are evenly distributed below half of the vertical height; the external chillers are cylindrical external chillers 1 with a size of ≥φ60mm×60mm, and the placement spacing is within 200mm.
[0034] 5) The integral casting 3 of the bucket lip starts to shake out and clean in the sand mold when it cools to below 300°C; then heat treatment is carried out: it is heated to 650°C at a heating rate of 70°C per hour and held for 3 hours, and then heated to 1050°C at a heating rate of 80°C per hour, and water toughening treatment is carried out after holding for more than 3 hours and then taken out of the furnace.
[0035] As Figure 3 shown, the positioning structure adopted for the heat treatment of the integral manufacturing of the large bucket lip includes the integral casting 3 of the bucket lip, the drag plate 4, and several limit fixing blocks 2. One side of the large flange plane ( Figure 1 the B surface in ) of the integral casting 3 of the bucket lip is placed on the drag plate 4, and several limit fixing blocks 2 are respectively arranged at the arc vertices of the integral casting 3 of the bucket lip, the middle parts of the arcs on both sides of the vertices, and the side walls of the bucket lip. The limit fixing blocks 2 at the arc vertices of the integral casting 3 of the bucket lip and the middle parts of the arcs on both sides of the vertices are arranged on both sides of the arc wall of the integral casting 3 of the bucket lip, and the limit fixing blocks 2 on the side walls of the bucket lip are arranged on the inner wall of the bucket lip. Several of the limit fixing blocks 2 are fixedly connected to the drag plate 4. Figure 3 The part view of the integral casting 3 of the bucket lip in Figure 1 is the view of the B surface in, and the position of the drag plate 4 is at the upper end of the view of the B surface. During heat treatment, the drag plate 4 is used to support the integral casting 3 of the bucket lip as a whole.
[0036] The limit fixing block 2 is a metal block.
[0037] The cross-section of the limit fixing block 2 is square, with a height of 100mm; the cross-sectional size is 140mm×80mm.
[0038] The performance of the casting after water toughening treatment of the present invention is: R m is 800MPa, A is 31%, Aku / J is 150, and HBW is 300.
[0039] During the overall casting process of the large bucket lip, there are two easily deformed stages that need to be particularly controlled. One stage is at the end of pouring. Due to different shrinkage rates in each part, the deformation of the two side vertical walls is serious. Vertical molding and casting are adopted, and gravity feeding is used. By controlling the pouring temperature and pouring time, the shrinkage rate at the bottom of the bucket lip is controlled within 25% - 28%, and the shrinkage rate at the top is controlled within 15% - 20%. The differential design of the shrinkage rates at the top and bottom of the casting can effectively control the deformation amount of the casting and ensure the dimensional accuracy of the casting. The second easily deformed stage is the heat treatment stage. During the heat treatment process of the casting of the present utility model, limit fixing blocks 2 are respectively arranged at the arc apex of the bucket lip, the middle of the arcs on both sides of the apex, and the side wall of the bucket lip, which can effectively control the deformation caused by the change of thermal stress during the heat treatment process and ultimately ensure the dimensional accuracy of the casting.
Claims
1. A positioning structure used for heat treatment of the lip of an integrally manufactured large bucket, characterized in that, It includes an integral casting of the bucket lip, a carriage, and several limit fixing blocks. One side of the flange large plane of the integral casting of the bucket lip is placed on the carriage. The several limit fixing blocks are respectively arranged at the arc vertex of the integral casting of the bucket lip, the middle parts of the arcs on both sides of the vertex, and the position of the side wall of the bucket lip. The limit fixing blocks at the arc vertex of the integral casting of the bucket lip and the middle parts of the arcs on both sides of the vertex are arranged on both sides of the arc wall of the integral casting of the bucket lip, and the limit fixing block on the side wall of the bucket lip is arranged on the inner wall of the bucket lip. The several limit fixing blocks are all fixedly connected to the carriage.
2. The positioning structure adopted for heat treatment of the integral manufactured large bucket lip according to claim 1, characterized in that, The integral casting of the bucket lip is a bucket lip casting with a volume of more than 55 cubic meters or a single weight exceeding 8 tons.
3. The positioning structure adopted for heat treatment of the integral manufacturing large bucket lip according to claim 1, characterized in that, The limit fixing block is a metal block.
4. A positioning structure used for heat treatment of an integrally manufactured large bucket lip according to any one of claims 1-3, characterized in that, The cross-section of the limit fixing block is square, and the height is 80 - 120 mm; the cross-sectional dimensions are (120 - 150) mm × (50 - 80) mm.