Forklift box closing machining process

Abstract

The invention discloses a box closing processing technology of a forklift box body, which is characterized in that the assembled and combined box body is subjected to integral semi-finish machining and finish machining, so that the shape and position precision between holes is high; especially, the coaxiality of the holes in the same axis and the parallelism position tolerance of the holes in parallel with the axis are easily and integrally guaranteed, the overall quality of the box body is improved, the precision is guaranteed, and the production efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of forklift box processing, in particular to a box processing technology of forklift box. BACKGROUND

[0002] The forklift box includes a front shell and a rear shell, and the front shell and the rear shell are processed by separate processing. After the processing of the front shell and the rear shell is completed, the front shell and the rear shell are assembled to form a box, so that the processing of the forklift box is completed. The above processing method has many shortcomings. The concentricity of the shaft hole of the assembled bearing of the front shell and the rear shell has a relatively high concentricity requirement. The above processing method cannot overcome the system error caused by the different precision of different machine tools and the reference error caused by the non-uniform positioning reference. The waste rate of the processed product is relatively high, and it is difficult to meet the market requirements. SUMMARY

[0003] In view of the above shortcomings of the prior art, the present application provides a box processing technology of forklift box. The front shell and the rear shell are processed respectively. Before the shaft hole and the counterbore are finished, the front shell and the rear shell are assembled to form a semi-finished product after the semi-finishing, and then the shaft hole and the counterbore on the same axis are finished at one time. In this way, the shape and position tolerance of the shaft hole and the counterbore are guaranteed, and the shape and position accuracy of the processed product are higher.

[0004] To achieve the above-mentioned purpose, the present application provides a processing technology of forklift box, comprising: Step one, the processing technology of the positioning reference of the assembling surface of the rear shell. The reverse tooling fixture takes the assembling blank surface of the rear shell and the circumferential outer wall of the rear shell as the reference. The reverse tooling fixture positions and clamps the rear shell through six-point positioning. The vertical machining center processes the positioning reference surface on the back surface of the rear shell, two first process positioning pin holes on the assembling surface, and the back surface processing part. The positioning reference surface on the back surface of the rear shell is the back surface of the assembling surface of the rear shell. An outwardly extending pressing boss is arranged on the back surface of the assembling surface, and the height of the pressing boss is lower than that of the assembling surface of the rear shell. Step two, the processing technology of the assembling surface of the rear shell and the rough processing hole system. The shell body of step one is turned over by 180°. The front tooling fixture positions and processes the assembling surface, the locking screw hole and various hole systems through the two first process positioning pin holes and the rear shell positioning reference surface processed in step one. The assembling surface and the locking screw hole of the rear shell are finished in place. The rough processing hole system is the hole for assembling the bearing, and has a semi-finishing and finishing allowance. The rough processing hole system of the rear shell is divided into a through hole and a blind hole in structure. Step one and step two are concentratedly processed on one machine tool, or step one and step two are processed on different machine tools. Step three, the front shell processing technology, the outer circle of the front shell base disc and the back of the end face of one point, the end face of the disc end face of two points and the outer circle of one point are used as the reference surface for positioning, and three stations are processed on a four-axis vertical machining center machine tool; the outer circle of the front shell base disc and the back of the end face of one point, the end face of the disc end face of two points and the outer circle of one point are used as the reference surface for positioning, which is realized by a first tooling fixture; the three-station processing on the four-axis vertical machining center includes rotation by the X-axis rotary table or processing the assembly surface, hole system rough machining and the second process positioning pin hole in the 0° station, wherein the front shell assembly surface, the front shell assembly surface locking screw hole and the second process positioning pin hole on the front shell, the hole for assembling the bearing on the rough machined front shell, the rough machined hole system of the front shell is divided into a through hole and a blind hole; the front shell is rotated to the +90° station to process the third process positioning pin hole, the positioning boss, the locking hole and the end face of the locking hole, wherein the positioning boss top surface on the outer wall of the front shell side surface, the third process positioning pin hole and the locking hole and the end face of the locking hole; the front shell is rotated to the -90° station to process the hole and the surface, and the hole on the other side of the front shell and the end face of the other end of the locking hole are precisely machined; Step four, the front shell and the rear shell assembly process, the front shell and the rear shell are assembled into a semi-finished box body after the assembly surface is precisely machined; the assembly is performed by inserting two positioning pins for assembly into the first process positioning pin hole of the rear shell and the second process positioning pin hole of the front shell, then locking the front shell and the rear shell with bolts and nuts, and finally extracting the assembly positioning pin; Step five, the semi-precision machining process of the semi-finished box body, the semi-finished box body assembled in step four is clamped by a second tooling fixture, the second tooling fixture uses the third positioning pin hole and the locking hole processed in step three as the positioning pin hole, and uses it as the reference surface for positioning, and at the same time, the second tooling fixture supports the end face of the locking hole; a four-axis horizontal machining center is used to semi-precision machine the semi-finished box body, the semi-precision machining includes all the rough machining allowance holes and end faces, the semi-precision machined holes are the through holes and blind holes for assembling bearings on the front shell and the rear shell, the semi-precision machined end faces are the end faces of the base disc and the end faces of the disc end disc, and the end faces of the box base, and the semi-precision machined holes and end faces leave machining allowance for the parts that need to be finally machined; Step six, the box base is used as the lower bearing seat, the machined upper bearing seat end face and the semi-precision machined lower bearing seat end face are assembled to form a bearing seat, wherein the upper bearing seat and the lower bearing seat are locked by bolts; Step seven, the use of a horizontal machining center for precision machining is to semi-precision machine the holes and end faces that leave machining allowance, the precision machining includes the through holes and blind holes for assembling bearings on the front shell and the rear shell, and the semi-precision machined end faces are the end faces of the base disc and the end faces of the disc end disc; at the same time, the inner hole of the bearing seat formed after step six is precisely milled.

[0005] Preferably, in the step five, the horizontal machining center first mills the end face of the end face disc, and then mills the through hole of the assembly bearing on the front shell and the blind hole coaxial with the through hole on the rear shell, and then translates the front shell and the rear shell, and then rotates the box to 180°, and then mills the through hole of the assembly bearing on the rear shell and the blind hole coaxial with the through hole on the front shell, and then rotates the box to 270°, and then mills the bottom surface of the bottom disc, and then mills the bottom of the front shell and the bolt hole on the bottom.

[0006] Preferably, the front tooling fixture and the rear tooling fixture are installed on the same first base plate, and the rear tooling fixture is arranged side by side with the front tooling fixture, the front tooling fixture comprises four first front support columns and two first front positioning pins, the four first front support columns are installed on the first base plate, the two first front positioning pins are installed on the first base plate and extend into the first process positioning pin hole, the top of the two first front positioning pins is lower than the assembly surface of the rear shell, a strip-shaped clamping block is arranged above each first front support column, the strip-shaped clamping block is used to press the top of the boss, and the top of the strip-shaped clamping block is lower than the assembly surface of the front shell, the first front support column abuts against the positioning reference surface of the bottom surface of the pressing boss, and the strip-shaped clamping block presses the top surface of the pressing boss; the rear tooling fixture comprises four first rear support tables and four first rear abutting bolts, the four first rear support tables are installed on the first base plate, the top of the first rear support table is in contact with the blank surface of the assembly surface of the rear shell, the four first rear abutting bolts are installed on the first base plate, the first rear abutting bolts are used to abut against the blank surface of the outer wall of the rear shell, a strip-shaped clamping block is arranged above each first rear support table, the strip-shaped clamping block is installed on the first base plate, and the strip-shaped clamping block abuts against the back surface of the assembly surface of the rear shell.

[0007] Preferably, the first fixture used in step three comprises: a second base plate, a V-shaped structure positioning and clamping device, a front shell base disc back positioning and clamping device, an end face disc surface positioning and clamping device, and an end face disc outer circle positioning and clamping device; the V-shaped structure positioning and clamping device, the front shell base disc back positioning and clamping device, the end face disc surface positioning and clamping device, and the end face disc outer circle positioning and clamping device are all installed on the second base plate; the V-shaped structure positioning and clamping device comprises a V-shaped block for positioning the outer circle of the base disc and a first clamping pressure block corresponding to the V-shaped block, and the first clamping pressure block extends into the cavity of the front shell base for pressing; the front shell base disc back positioning and clamping device comprises a first screw for positioning the back surface of the front shell base disc and a first manual clamping screw rod corresponding to the back surface positioning screw; the end face disc surface positioning and clamping device comprises a supporting rod for positioning the surfaces of the two end face discs and a second clamping pressure block for pressing the surfaces of the end face discs, and each supporting rod corresponds to the second clamping pressure block in an up-down manner; the end face disc outer circle positioning and clamping device comprises an end face disc outer circle positioning screw and a second manual clamping screw rod corresponding to the end face disc outer circle positioning screw; and the first fixture used in step three is installed in a four-axis vertical machining center machine tool.

[0008] Preferably, the bottom disc is clamped between the first screw and the first manual clamping screw rod, and the first screw and the first manual clamping screw rod are coaxially arranged; a fixing seat is installed on the second base plate, the first manual clamping screw rod passes through the fixing seat, and the first manual clamping screw rod is in threaded connection with the fixing seat.

[0009] Preferably, an installation table is installed on the second base plate, an embedded groove recessed downward is formed in the installation table, the end face disc outer circle positioning screw and the second manual clamping screw rod are respectively installed on the inner walls on the two sides of the embedded groove, the second manual clamping screw rod passes through the inner walls of the embedded groove, and the second manual clamping screw rod is in threaded connection with the inner walls of the embedded groove, and the end face disc outer circle positioning screw and the second manual clamping screw rod are coaxial.

[0010] Preferably, the two second clamping pressure blocks are installed on an arc-shaped connecting plate, a groove accommodating the end face discs is formed in the arc-shaped connecting plate, a screw rod with a nut is installed between the arc-shaped connecting plate and the second base plate and between the first clamping pressure block and the second base plate, and the arc-shaped connecting plate and the first clamping pressure block are pressed by the nuts on the two screw rods.

[0011] Preferably, the second fixture used in step five or step seven comprises a third base plate, a cylindrical pin, a rhombic pin, a positioning surface, a gantry clamping device, three positioning surfaces are installed on the third base plate, the three positioning surfaces have a step difference, the three positioning surfaces are respectively in contact with the end surface of the third process positioning pin hole, the end surface of the positioning boss and the end surface of the lock hole on the front shell, wherein the positioning surface in contact with the positioning boss plays a main positioning role, and the other two positioning surfaces mainly play a supporting role, a rhombic pin extending into the third process positioning pin hole and a cylindrical pin extending into the lock hole are respectively installed on the two positioning surfaces playing a supporting role, a gantry clamping device located above the rhombic pin and a strip-shaped clamping block located above the cylindrical pin are installed on the third base plate.

[0012] Compared with the prior art, the advantages of the present application are that the assembled box body is subjected to integral semi-finishing and finishing, so that the shape and position accuracy between holes are guaranteed, especially the coaxiality of holes on the same axis, the parallelism of holes on parallel axes and position tolerances are easily guaranteed as a whole, the overall quality of the box body is improved, the accuracy is guaranteed, and the production efficiency is improved. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 It is a schematic view of the forklift box body of the present application.

[0014] Figure 2 It is a schematic view of the front shell and the rear shell of the present application. Figure 3 It is a schematic view of the rear shell of the present application.

[0015] Figure 4 It is a schematic view of the front fixture and the reverse fixture clamping the rear shell of the present application.

[0016] Figure 5 It is a schematic view of the front fixture and the reverse fixture of the present application.

[0017] Figure 6 It is a schematic view of the front shell clamped by the first fixture of the present application.

[0018] Figure 7 It is a schematic view of the first fixture of the present application.

[0019] Figure 8 It is a schematic view of the workpiece clamped by the second fixture of the present application.

[0020] Figure 9 It is a schematic view of the second fixture of the present application.

[0021] Wherein, 1, front shell, 2, rear shell, 3, positioning reference surface, 4, first process positioning pin hole, 5, second process positioning pin hole, 6, third process positioning pin hole, 7, front shell assembly surface, 8, rear shell assembly surface, 9, pressing boss, 10, lock hole, 11, positioning boss, 12, upper bearing seat, 13, bottom surface disc, 14, end surface disc, 15, front face tooling fixture, 16, first front face support column, 17, first front face positioning pin, 18, back face tooling fixture, 19, first back face support table, 20, first back face abutting bolt, 21, first base plate, 22, first tooling fixture, 23, second base plate, 24, V-shaped structure positioning clamping device, 25, V-shaped block, 26, first clamping pressing block, 27, front shell base disc back surface positioning clamping device, 28, first screw, 29, first manual clamping screw rod, 30, end surface disc positioning clamping device, 31, supporting rod, 32, second clamping pressing block, 33, end surface disc outer circle positioning clamping device, 34, end surface disc outer circle positioning screw, 35, second manual clamping screw rod, 36, fixed seat, 37, mounting table, 38, embedded groove, 39, arc-shaped connecting plate, 40, second tooling fixture, 41, third base plate, 42, positioning surface, 43, cylindrical pin, 44, rhombic pin, 45, gantry type clamping device. DETAILED DESCRIPTION

[0022] The application will be further described in conjunction with the drawings.

[0023] As Figures 1-9 shown, a forklift box machining process, comprising: Step one, the process of positioning the assembling surface of the rear shell 2, the back tooling fixture is installed on the vertical machining center by bolts, the first tooling fixture 22 is positioned and clamped on the rear shell 2 by taking the assembling blank surface of the rear shell 2 and the circumferential outer wall of the rear shell 2 as the reference, that is, the first tooling fixture 22 positions and clamps the rear shell 2 by six-point positioning, the vertical machining center processes the positioning reference surface 3 on the back of the rear shell 2 and the two first process positioning pin holes 4 on the assembling surface, and processes the back processing part, the positioning reference surface 3 on the back of the rear shell 2 is the back of the rear shell assembling surface 8, wherein the outwardly extending pressing boss 9 is arranged on the back of the assembling surface, the required positioning reference surface 3 is the back of the mounting boss, the height of the pressing boss 9 is lower than that of the rear shell assembling surface 8, when the assembling surface needs to be processed, the assembling surface needs to face upwards, if the pressing boss 9 is not arranged, it needs to be directly pressed on the assembling surface, which affects the processing of the assembling surface, the pressing boss 9 protruding from the assembling surface is arranged on the back of the assembling surface by integral casting, so that when the positioning reference surface 3 is milled, only the backs of the four pressing bosses 9 need to be milled, at the same time, the vertical machining center drills the first process positioning pin hole 4 through the assembling surface from the back of the rear shell 2, the two first process positioning pin holes 4 are located on the diagonal lines of the rear shell 2, so as to ensure the positioning accuracy in the subsequent process, and the vertical machining center processes the back processing part, wherein two groups of blind holes for mounting bearings and one group of through holes for mounting bearings are arranged on the rear shell 2, and the through hole for mounting the bearing is located between the two groups of blind holes, the end face of the above-mentioned through hole on the back of the rear shell 2 is milled by the vertical machining center, and the end face of the above-mentioned through hole is the back processing part.

[0024] Step two, the process of processing the assembling surface of the rear shell 2 and the rough processing hole system, the shell body of step one is turned over by 180°, the front tooling fixture 15 is installed on the vertical machining center by bolts, the front tooling fixture 15 is positioned by the two first process positioning pin holes 4 and the positioning reference surface 3 on the pressing boss 9 of the rear shell 2 processed in step one, the vertical machining center processes the assembling surface, the locking screw hole and various hole systems, wherein the assembling surface of the rear shell 2 is precisely milled in place, and one more locking screw hole is precisely machined in place, the rough processing hole system is a hole for assembling the bearing, the above-mentioned hole is located in the inner cavity of the rear shell 2, and has a semi-finishing and finishing allowance, the rough processing hole system of the rear shell 2 is divided into a blind hole and a through hole in structure, two groups of blind holes for mounting bearings and one group of through holes for mounting bearings are arranged in the inner cavity of the rear shell 2, and the through hole for mounting the bearing is located between the two groups of blind holes; the front tooling fixture 15 and the back tooling fixture 18 of step one and step two are installed on the same vertical machining center, and the back and front of the rear shell 2 are processed by the same vertical machining center; the front tooling fixture 15 and the back tooling fixture 18 of step one and step two can also be installed on two independent vertical machining centers for processing.

[0025] Step 3, Front Shell 1 Machining Process: The first tooling fixture 22 is installed on an independent vertical machining center. The first tooling fixture 22 is positioned using the outer circle and a point on the back of the end face of the base disk of the front shell 1, and two points on the end face of the end face disk 14 and a point on the outer circle as reference surfaces (the positioning reference surface 3 on the front shell 1 is machined using the blank surface as the positioning reference surface). Machining is performed in three stations on a four-axis vertical machining center (machining the three surfaces of the front shell 1 by rotating the front shell 1); First, on a four-axis vertical machining center... At the 0° station, the assembly surface, hole system rough machining, and the second process positioning pin hole 5 on the assembly surface are processed. This includes finish milling the front housing assembly surface 7, finish machining the locking screw hole on the front housing assembly surface 7, and the second process positioning pin hole 5 on the front housing 1. The locking screw hole on the front housing 1 is tapped. The holes on the front housing 1 for mounting bearings are rough machined. The rough-machined holes on the front housing 1 are structurally divided into two sets of through holes and one set of blind holes. The bearing mounting holes on the front housing 1 are located inside the front housing 1 cavity, and the blind holes for mounting bearings inside the front housing 1 are located within the two sets of through holes. Between; the front shell 1 is rotated to a +90° position to machine the third process positioning pin hole 6, positioning boss 11, lock hole 10 and the end face of one end of the lock hole 10, wherein the top surface of the positioning boss 11 on the outer side wall of the front shell 1 is finished, the end face of the third process positioning pin hole 6 and the end face of the third process positioning pin hole 6, the lock hole 10 and the end face of one end of the lock hole 10 are finished; the front shell 1 is rotated to a -90° position to machine the hole and the surface, and the end face of the hole and the other end of the lock hole 10 on the other side of the front shell 1 is finished; the above-mentioned front shell 1 assembly The mounting surface is used for splicing with the rear shell 2. The second process positioning pin hole 5 is used to position with the first process positioning pin hole 4 of the front shell 1 during splicing. Then, the bolt is inserted from the locking screw hole of the rear shell 2 into the locking screw hole of the front shell 1. The bolt is used to lock the front shell 1 and the rear shell 2 after splicing. The third process positioning pin hole 6, the locking hole 10, the positioning boss 11 and the end face of the locking hole 10 serve as positioning references for subsequent processing. At the same time, the third process pin hole and the hole on the other side of the front shell 1 also serve as the oil hole of the subsequent forklift box.

[0026] Step 4: Assembly of front shell 1 and rear shell 2. After the front shell 1 and rear shell 2 have been finished, their assembly surfaces are fitted together to assemble them into a semi-finished box body. The assembly is carried out by inserting two assembly positioning pins into the first process positioning pin hole 4 of the rear shell 2 and the second process positioning pin hole 5 of the front shell 1 for positioning. Then, the front shell 1 and rear shell 2 are locked with bolts and nuts. Finally, the assembly positioning pins are pulled out, thus completing the assembly of the forklift box body.

[0027] Step five, semi-finished box semi-finishing process, the assembled semi-finished box of step four is clamped by the second fixture 40, the second fixture 40 is installed on the rotary table of the horizontal machining center by bolts, the forklift box is rotated around the Z axis by the rotary table, the second fixture 40 is positioned with the third positioning pin hole and the lock hole 10 as the positioning pin hole, and the positioning boss 11 after fine milling as the reference surface, and the end surface of the lock hole 10 is supported by the second fixture 40; a four-axis horizontal machining center is used to semi-finish the semi-finished box, the semi-finished box includes all the rough machining allowance hole system and end surface, the semi-finished hole system is the through hole and blind hole for assembling bearing on the front shell 1 and rear shell 2, the semi-finished end surface is the end surface of the base disc and the end surface of the end surface disc 14, and the end surface of the box base, the semi-finished hole system and end surface leave a finishing allowance for the last finishing part; when semi-finishing, the horizontal machining center first rough mills the end surface of the end surface disc 14 of the front shell 1, then semi-finishes the end surface of the end surface disc 14, semi-borings the through hole for installing bearing on the end surface disc 14, the boring cutter continues to extend and semi-borings the blind hole coaxial with the above-mentioned through hole on the rear shell 2, after retraction, the boring cutter extends into another through hole for installing bearing on the front shell 1 and semi-borings the through hole, the corresponding semi-borings the blind hole coaxial with the above-mentioned through hole, the forklift box rotates 180° clockwise, the boring cutter semi-borings the through hole for installing bearing on the rear shell 2, then semi-borings the blind hole for installing bearing on the rear shell 2, then the forklift box rotates 90° clockwise, the horizontal machining center rough mills and semi-finishes the bottom surface of the base disc, thus completing the semi-finishing of the forklift box and leaving a margin for finishing.

[0028] Step six, when the base disc semi-finishing in step five is completed, the horizontal machining center semi-mills the end surface of the box base, and the bolt hole is provided on the semi-milled base of the box by drilling and tapping, so that the box base serves as the lower bearing seat, the end surface of the upper bearing seat 12 is milled and drilled after the bolt hole, the end surface of the upper bearing seat 12 is attached to the end surface of the lower bearing seat, and the upper bearing seat 12 is locked with the lower bearing seat by bolts.

[0029] Step seven, the use of horizontal machining center finishing is to semi-finishing finishing allowance hole system and end face, the finishing content includes the through hole and blind hole of the bearing assembly on the front shell 1 and the rear shell 2, the semi-finishing end face is the end face of the base disc and the end face of the end face disc 14, and the inner hole of the bearing seat formed after step six is assembled is precisely milled; after the above-mentioned worker installs the upper bearing seat 12 in the box body base, the box body is rotated clockwise by 90°, the horizontal machining center precisely mills the end face of the end face disc 14, precisely bores the through hole of the bearing installed on the end face disc 14, the boring cutter continues to extend and precisely bores the blind hole coaxial with the above-mentioned through hole on the rear shell 2, after the boring cutter is withdrawn, the boring cutter extends into another through hole of the front shell 1 for installing the bearing and precisely bores the through hole, the corresponding blind hole coaxial with the above-mentioned through hole is precisely bored, the inner hole formed by the splicing of the upper bearing seat 12 and the lower bearing seat is precisely milled; the forklift box body is rotated clockwise by 180°, the boring cutter precisely bores the through hole of the bearing installed on the rear shell 2, then the boring cutter semi-precisely bores the blind hole of the bearing installed on the rear shell 2, then the forklift box body is rotated clockwise by 90°, the horizontal machining center precisely mills the bottom surface of the base disc, thus completing the whole machining content of the forklift box body, and after the machining is completed, the pressing boss 9 can be cut.

[0030] The front tooling fixture 15 and the back tooling fixture 18 are bolted on the same first base plate 21, and the back tooling fixture 18 is arranged side by side with the front tooling fixture 15, the front tooling fixture 15 and the back tooling fixture 18 are arranged side by side on the first base plate 21, the front tooling fixture 15 includes the first front supporting column 16 and the first front positioning pin 17, four first front supporting columns 16 are bolted on the first base plate 21, two groups of first front positioning pins 17 (two groups of first front positioning pins 17 are cylindrical pins 43 and rhombus pins 44) are bolted on the first base plate 21, two first front positioning pins 17 extend into the first process positioning pin hole 4, and the top of the two first front positioning pins 17 is lower than the assembly surface of the rear shell 2, so as to facilitate the processing of the assembly surface, a strip-shaped clamping pressing block is arranged above each first front supporting column 16, the strip-shaped clamping pressing block presses the top of the boss, and the top surface of the strip-shaped clamping pressing block is lower than the assembly surface of the front shell 1, the first front supporting column 16 is located on the positioning reference surface 3 of the bottom surface of the pressing boss 9, and the strip-shaped clamping pressing block presses the top surface of the pressing boss 9; the back tooling fixture 18 includes the first back supporting table 19 and the first back abutting bolt 20, four first back supporting tables 19 are bolted on the first base plate 21, the top of the first back supporting table 19 is in contact with the blank surface of the rear shell assembly surface 8, four first back abutting bolts 20 are bolted on the first base plate 21 in a bolted manner, a plurality of bolt seats are bolted on the first base plate 21 in a bolted manner, each first back abutting bolt 20 passes through the bolt seat, the first back abutting bolt 20 is in threaded connection with the bolt seat, the extension amount is adjusted by rotating the first back abutting bolt 20, the rear shell 2 outer wall blank surface is abutted by the plurality of first back abutting bolts 20, and a strip-shaped clamping pressing block is arranged above each first back supporting table 19.

[0031] The strip-shaped clamping pressing block is provided with a waist-shaped hole, a screw rod passes through the waist-shaped hole, a nut is sleeved on the screw rod, the nut is pressed on the top surface of the strip-shaped clamping pressing block, one end of the strip-shaped clamping pressing block is pressed on the rear shell 2, a screw rod is arranged below the other end of the strip-shaped clamping pressing block, a threaded sleeve is further arranged on the screw rod, the other end of the strip-shaped clamping pressing block is pressed on the top surface of the threaded sleeve, and the screw rod and the screw rod are fixed on the first base plate 21 by welding.

[0032] The first tool fixture 22 used in step three comprises a second base plate 23, a V-shaped structure positioning and clamping device 24, a front shell base disc back positioning and clamping device 27, an end face disc 14 face positioning and clamping device, and an end face disc outer circle positioning and clamping device 33. The V-shaped structure positioning and clamping device 24, the front shell base disc back positioning and clamping device 27, the end face disc 14 face positioning and clamping device, and the end face disc outer circle positioning and clamping device 33 are all installed on the second base plate 23. The V-shaped structure positioning and clamping device 24 comprises a V-shaped block 25 for positioning the outer circle of the base disc and a first clamping pressure block 26 corresponding to the V-shaped block 25. The bottom of the V-shaped block 25 is installed on the second base plate 23 through a bolt, and the top of the V-shaped block 25 is a V-shaped groove. When the front shell 1 is positioned, the circumferential surface of the bottom disc 13 of the front shell 1 is clamped in the V-shaped groove, and the outer wall of the bottom disc 13 is positioned by the V-shaped groove. The first clamping pressure block 26 is a strip-shaped clamping pressure block, and the screw rod of the strip-shaped clamping pressure block is fixed on the second base plate 23. The first clamping pressure block 26 extends into the cavity of the front shell 1 base for pressing. The front shell base disc back positioning and clamping device 27 comprises a first screw 28 for positioning the back of the front shell 1 base disc and a first manual clamping screw rod 29 corresponding to the back first screw 28. Two seat bodies are installed on the second base plate 23 through bolt fastening, and the seat bodies are located on the left and right sides of the V-shaped block 25. The first screw 28 is fixed when clamping and positioning. When positioning and clamping are needed, the first manual clamping screw rod 29 is rotated to clamp the left and right ends of the bottom disc 13 through the first manual clamping screw rod 29 and the first screw 28. The end face disc 14 face positioning and clamping device comprises a supporting rod 31 for positioning the faces of the two end face discs 14 and a second clamping pressure block 32 for pressing the faces of the end face discs 14. Each supporting rod 31 corresponds to a second clamping pressure block 32 in an up-down manner. The bottom of the supporting rod 31 is fixed on the second base plate 23 through a bolt, and the top of the supporting rod 31 abuts against the bottom of the end face disc 14. The end face disc outer circle positioning and clamping device 33 comprises an end face disc outer circle positioning screw 34 and a second manual clamping screw rod 35 corresponding to the end face disc outer circle positioning screw 34. The outer circumferential surface of the end face disc 14 is clamped by the end face disc outer circle positioning screw 34 and the second manual clamping screw rod 35, so that the first tool fixture 22 positions and clamps the front shell 1. The first tool fixture 22 used in step three is installed in a four-axis vertical machining center machine tool.

[0033] The bottom disc 13 is clamped between the first screw 28 and the first manual clamping screw 29, and the first screw 28 and the first manual clamping screw 29 are coaxially arranged between the first screw 28 and the first manual clamping screw 29. The fixing seat 36 is installed on the second base plate 23 by bolt fastening, and the fixing seat 36 is two groups and located on the left and right sides of the bottom disc 13. The first screw 28 and the first manual clamping screw 29 pass through the fixing seat 36, and the first screw 28 and the first manual clamping screw 29 are screwed with the fixing seat 36. The extension amount of the first screw 28 and the first manual clamping screw 29 is adjusted by rotating the first screw 28 and the first manual clamping screw 29. Since the first screw 28 is a fixed part, the first screw 28 does not rotate when the front shell 1 is positioned and clamped. Only when the thickness of the bottom disc 13 of the front shell 1 changes, adaptive adjustment is made. When the bottom disc 13 needs to be clamped, the first manual clamping screw 29 is rotated, so that the first manual clamping screw 29 pushes the front shell 1 to the left, so that the left end face of the bottom disc 13 contacts the end of the first screw 28, and the bottom disc 13 is clamped by the first screw 28 and the first manual clamping screw 29.

[0034] The mounting table 37 is installed on the second base plate 23 by bolt fastening, and the mounting table 37 extends upward. The embedding groove 38 is opened downward on the top surface of the mounting table 37. The outer circle positioning screw 34 and the second manual clamping screw 35 pass through the outer wall of the embedding groove 38 and extend into the embedding groove 38. The outer circle positioning screw 34 and the second manual clamping screw 35 are screwed with the outer wall of the embedding groove 38. The outer circle positioning screw 34 and the second manual clamping screw 35 are coaxial. When positioning and clamping, the outer circle positioning screw 34 does not rotate, and the second manual clamping screw 35 rotates and abuts against the outer wall of the end disc 14. The outer circle positioning screw 34 and the second manual clamping screw 35 abut against the outer wall of the end disc 14, and the outer circle positioning screw 34 and the second manual clamping screw 35 are both towards the center of the end disc 14.

[0035] The two second clamping blocks 32 are fixed at the bottom of both ends of the arc-shaped connecting plate 39 by welding, the arc-shaped connecting plate 39 is provided with a circular arc-shaped slot for the positioning of the end face disc 14, a screw rod is installed between the arc-shaped connecting plate 39 and the second base plate 23, the arc-shaped connecting plate 39 is provided with a waist-shaped hole, the screw rod passes through the waist-shaped hole, a nut is sleeved on the screw rod for pressing the arc-shaped connecting plate 39, a screw rod sleeved with a nut is installed between the first clamping block 26 and the second base plate 23, the first clamping block is also provided with a waist-shaped hole for the screw rod to pass through, the nut on the screw rod is pressed on the first clamping block, the arc-shaped connecting plate 39 and the first clamping block 26 are pressed by the screw nuts on the two screw rods, so that the front shell 1 is pressed tightly, and a screw rod is fixed on the second base plate 23 below the tail of the arc-shaped connecting plate 39 by welding, a threaded sleeve is further sleeved on the screw rod, and the first clamping block and the tail of the arc-shaped connecting plate 39 are pressed on the top surface of the threaded sleeve.

[0036] The second fixture 40 used in step five or step seven comprises a third base plate 41, a cylindrical pin 43, a rhombic pin 44, a positioning surface 42, a gantry clamping device 45, and a strip-shaped clamping block. Three positioning surfaces 42 are installed on the third base plate 41 by bolt fastening. The three positioning surfaces 42 have a step difference and are respectively in contact with the end surface of the third process positioning pin hole 6, the end surface of the positioning boss 11, and the end surface of the lock hole 10 on the front shell 1. The positioning surface 42 in contact with the positioning boss 11 plays a major positioning role, and the other two positioning surfaces 42 mainly play a supporting role. Installation holes are opened in the two positioning surfaces 42 that play a supporting role and are tapped. A bolt is installed at the bottom of the cylindrical pin 43 and the rhombic pin 44 by welding. The bolt extends into the installation hole and is fixed by threaded cooperation. A gantry clamping device 45 is installed above the rhombic pin 44 on the third base plate 41. The gantry clamping device 45 comprises a column, a support plate, and a pressing plate. Two columns are fixed on the third base plate 41 on the front and rear sides of the box by welding. A screw rod with a smaller radius than the column is fixed on the top of the column by welding. A nut is sleeved on the screw rod. Two U-shaped holes are opened at the ends of the support plate. One U-shaped hole is located on the end surface of one end of the support plate, and the other U-shaped hole is located on the side surface close to the other end of the support plate. When needed, the U-shaped hole of the support plate is clamped onto the screw rod of the column. A nut is sleeved on the screw rod, and the support plate is pressed by the nut. A pressing plate is arranged below the support plate. Pressing blocks are fixed on the bottom of the pressing plate at both ends by welding. The bottom of the pressing block is an arc surface that is in contact with the surface of the box. The pressing block presses on the outer wall of the box. A guide rod is fixed on the top of the pressing plate by welding. The guide rod passes through the support plate. The pressing plate rises and falls along the guide rod. An adjusting bolt passes through the support plate. The adjusting bolt is in threaded cooperation with the support plate. The bottom of the adjusting bolt presses on the support plate. A strip-shaped clamping block is installed above the cylindrical pin 43 on the third base plate 41. The strip-shaped clamping block has the same structure as the strip-shaped clamping block on the first base plate 21.

Claims

1. A forklift box assembly process, characterized in that: Step one, the process of positioning the assembly surface of the rear shell, the reverse tooling fixture taking the rear shell assembly blank surface and the rear shell circumferential outer wall as the reference, the reverse tooling fixture positioning and clamping the rear shell through six-point positioning, the vertical machining center machining the positioning reference surface on the back of the rear shell, as well as two reverse process positioning pin holes on the assembly surface and the machining part on the back, the positioning reference surface on the back of the rear shell being the back of the rear shell assembly surface, wherein a pressing boss is provided on the back of the assembly surface, the height of the pressing boss being lower than the rear shell assembly surface; Step two, the process of machining the assembly surface of the rear shell and the process of rough machining the hole system, the shell body of step one being turned over by 180°, the front tooling fixture positioning and machining the assembly surface, locking screw holes and various hole systems with the two first process positioning pin holes and the rear shell positioning reference surface machined in step one, wherein the assembly surface and the locking screw holes of the rear shell are precisely machined in place, the rough machining hole system being the hole for assembling bearings, leaving a semi-finishing and finishing allowance, the rough machining hole system of the rear shell being divided into through holes and blind holes in structure; the step one and the step two being concentratedly machined on one machine tool, or the step one and the step two being machined on different machine tools; Step three, the process of machining the front shell, taking the outer circle of the front shell base disc and one point on the back of the end face, two points on the end face of the end face disc and one point on the outer circle as the reference surface for positioning, and performing three station machining on one four-axis vertical machining center; the positioning of the outer circle of the front shell base disc and one point on the back of the end face, two points on the end face of the end face disc and one point on the outer circle as the reference surface being achieved through the first tooling fixture; the three station machining on one four-axis vertical machining center including achieving through X-axis rotary table rotation or machining the assembly surface, hole system rough machining and machining the second process positioning pin hole of the assembly surface at the 0° station, wherein the assembly surface of the front shell, the locking screw hole on the assembly surface of the front shell and the second process positioning pin hole on the front shell are precisely machined, the hole for assembling bearings on the front shell being rough machined, the rough machining hole system of the front shell being divided into through holes and blind holes in structure; the front shell being rotated to the +90° station to machine the third process positioning pin hole, the positioning boss, the locking hole and the end face of the locking hole, wherein the positioning boss top surface on the outer wall of the side face of the front shell, the third process positioning pin hole and the locking hole and the end face of the locking hole are precisely machined; the front shell being rotated to the -90° station to machine the hole and the face, the hole on the other side face of the front shell and the end face of the other end of the locking hole being precisely machined; Step four, the assembly process of the front shell and the rear shell, the front shell and the rear shell being assembled into a semi-finished box body by pasting the precisely machined assembly surfaces; the assembly being achieved by inserting two positioning pins for assembly into the first process positioning pin hole of the rear shell and the second process positioning pin hole of the front shell for positioning, then locking the front shell and the rear shell with bolts and nuts, and finally extracting the positioning pins for assembly; Step five, semi-finished box semi-finishing process, the assembled semi-finished box of step four is clamped by a second fixture, the second fixture uses the third positioning pin hole and the lock hole processed in step three as the positioning pin hole to position the reference surface, and the end surface of the lock hole is supported by the second fixture; a four-axis horizontal machining center is used to semi-finish the semi-finished box, the semi-finished box includes all the rough machining allowance hole system and end surface, the semi-finished hole system is the through hole and blind hole for assembling bearings on the front shell and rear shell, the semi-finished end surface is the end surface of the base disc and the end surface of the end surface disc, and the end surface of the box base, and the semi-finished hole system and end surface leave a finishing allowance for the parts that need to be finished finally; Step six, the box base is used as a lower bearing seat, the upper bearing seat end surface processed and the semi-finished lower bearing seat end surface are assembled to form a bearing seat, and the upper bearing seat and the lower bearing seat are locked by bolts; Step seven, the horizontal machining center is used for finishing the hole system and end surface with finishing allowance after semi-finishing, and the finishing content includes the through hole and blind hole for assembling bearings on the front shell and rear shell, and the semi-finished end surface is the end surface of the base disc and the end surface of the end surface disc; and the bearing seat inner hole formed after step six is assembled is precisely milled.

2. The process for splicing of a fork truck body as set forth in claim 1, wherein, In step five, the horizontal machining center first semi-finishes the end surface of the end surface disc, semi-finishes the through hole for assembling bearings on the front shell located on the end surface disc and the blind hole coaxial with the through hole on the rear shell, the horizontal machining center translates to semi-finish another through hole for assembling on the front shell and the blind hole coaxial with the through hole on the rear shell, the box is rotated to 180°, the horizontal machining center semi-finishes the through hole for assembling bearings on the rear shell and the blind hole coaxial with the through hole on the front shell; the box is rotated to 270°, the horizontal machining center plate semi-finishes the bottom surface of the base disc, simultaneously, the horizontal machining center plate semi-finishes the base of the front shell, and a bolt hole is formed on the base, the semi-finished base of the front shell and the bolt hole formed on the base are used for step six and the upper bearing seat assembly.

3. The process for block joining of a fork truck body as defined in claim 1 wherein, The front face tooling fixture and the back face tooling fixture are installed on the same first base plate, and the back face tooling fixture is arranged side by side with the front face tooling fixture, the front face tooling fixture comprises first front face support columns and first front face positioning pins, four first front face support columns are installed on the first base plate, two groups of first front face positioning pins are installed on the first base plate, two first front face positioning pins extend into the first process positioning pin hole, and the top of the two first front face positioning pins is lower than the assembly surface of the rear shell, a strip-shaped clamping pressing block is arranged above each first front face support column, the strip-shaped clamping pressing block is used for pressing the top of the boss, and the top surface of the strip-shaped clamping pressing block is lower than the assembly surface of the front shell, the first front face support column is located on the positioning reference surface of the bottom surface of the pressing boss, and the strip-shaped clamping pressing block is pressed on the top surface of the pressing boss; the back face tooling fixture comprises first back face support tables and first back face abutting bolts, four first back face support tables are installed on the first base plate, the top of the first back face support table is in contact with the blank surface of the assembly surface of the rear shell, and four first back face abutting bolts are installed on the first base plate; the blank surface of the outer wall of the rear shell is abutted through the first back face abutting bolts, a strip-shaped clamping pressing block is arranged above each first back face support table, the strip-shaped clamping pressing block is installed on the first base plate, and the strip-shaped clamping pressing block is pressed on the back surface of the assembly surface of the rear shell.

4. The first fixture for use in step three of the process for welding the sides of a fork truck box together of claim 1 comprising: The second base plate, the V-shaped structure positioning and clamping device, the front shell base disc back surface positioning and clamping device, the end surface disc surface positioning and clamping device, and the end surface disc outer circle positioning and clamping device are installed on the second base plate; the V-shaped structure positioning and clamping device comprises a V-shaped block for positioning the outer circle of the base disc and a first clamping pressing block corresponding to the V-shaped block, and the first clamping pressing block extends into the cavity of the front shell base for pressing; the front shell base disc back surface positioning and clamping device comprises a first screw for positioning the back surface of the front shell base disc and a first manual clamping screw rod corresponding to the back surface positioning screw; the end surface disc surface positioning and clamping device comprises a supporting rod for positioning two end surface disc surfaces and a second clamping pressing block for pressing the end surface disc surface, and each supporting rod corresponds to the second clamping pressing block in an up-down mode; the end surface disc outer circle positioning and clamping device comprises an end surface disc outer circle positioning screw and a second manual clamping screw rod corresponding to the end surface disc outer circle positioning screw; the first tooling fixture used in step three is installed in the four-axis vertical machining center machine tool.

5. A process for welding the sides of a fork truck body as defined in claim 4 wherein, The bottom disc is clamped between the first screw and the first manual clamping screw rod, the first screw and the first manual clamping screw rod are coaxially arranged, a fixing seat is installed on the second base plate, the first manual clamping screw rod penetrates through the fixing seat, and the first manual clamping screw rod is in threaded connection with the fixing seat.

6. The process of claim 4, wherein, The mounting table is installed on the second base plate, and a downward recessed embedding groove is opened on the mounting table. The end face disc outer circle positioning screw and the second manual clamping screw are respectively installed on the inner walls of both sides of the embedding groove. The second manual clamping screw passes through the inner wall of the embedding groove, and the second manual clamping screw is in threaded cooperation with the inner wall of the embedding groove. The end face disc outer circle positioning screw and the second manual clamping screw are coaxial.

7. The process of claim 4, wherein, Two second clamping blocks are installed on the arc-shaped connecting plate. The arc-shaped connecting plate is provided with a groove body for accommodating the end face disc. A screw rod with a nut is installed between the arc-shaped connecting plate and the second base plate and between the first clamping block and the second base plate. The arc-shaped connecting plate and the first clamping block are pressed through the nut.

8. The second fixture used in step five or step seven of the box closing process of the fork truck box body of claim 1 comprises a third base plate, a cylindrical pin, a rhombic pin, a positioning surface, a gantry clamping device, and a strip-shaped clamping block. Three positioning surfaces are installed on the third base plate. The three positioning surfaces have a step difference. The three positioning surfaces are respectively in contact with the end face of the third process positioning pin hole, the positioning boss, and the lock hole on the front shell. The positioning surface in contact with the positioning boss plays a main positioning role, and the other two positioning surfaces mainly play a supporting role. The rhombic pin inserted into the third process positioning pin hole and the cylindrical pin inserted into the lock hole are respectively installed on the two positioning surfaces playing a supporting role. A gantry clamping device above the rhombic pin and a strip-shaped clamping block above the cylindrical pin are installed on the third base plate.

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