Tool changing mechanism of machining center and tool changing method

Abstract

Processing center opening type tool changing mechanism, including frame, tool magazine, spindle, spindle guide rail, tool changing arm and control system, tool magazine includes tool magazine stand, tool cup chain assembly and tool lifting assembly, tool cup chain assembly is opened with tool changing opening matched with tool lifting assembly, the tool moving to tool changing opening enters into tool lifting assembly;The tool changing arm includes drive box, arm shaft connected with the drive box transmission and the tool changing clamping piece installed on the front end of the arm shaft, the arm shaft is set in the front of the tool magazine and rotates and stretches out with the transmission of the drive box, the tool changing clamping piece stretches into the tool changing opening between the spindle with the forward extension of the arm shaft, and is vertically aligned with the tool entering into the tool lifting assembly and the tool on the spindle, so that the tool is clamped in the tool changing clamping piece with the movement of the tool lifting assembly and the spindle.The tool changing efficiency of the present application is high, and the tool changing automation level is high.The present application also provides a kind of tool changing method of processing center opening type tool changing mechanism.

Description

Technical Field

[0001] This invention relates to an open-type tool changer mechanism and tool changing method for a machining center, belonging to the field of automatic tool changing technology for machining centers. Background Technology

[0002] Currently, more and more CNC machine tools are equipped with robotic tool magazines to complete the machining of complex parts in one setup, thereby improving machining efficiency. Especially for horizontal machining centers, with the development of CNC machine tool technology, more and more CNC machine tools are equipped with automatic tool change systems, which greatly improves the machining efficiency of CNC machine tools.

[0003] An automatic tool changer system includes a tool changing mechanism and a tool magazine that can store multiple tools. The tool magazine is often a standard configuration. Its main function is to provide tool storage locations and, under program control, correctly select and position the tools for exchange. Common types include duct-type, chain-type, and gantry-type tool magazines. The tool changing mechanism typically uses a tool-grabbing arm to pick up the tools. However, this arm is only suitable for single-layer tool magazines, which have a limited capacity. Increasing the number of tools a single-layer magazine can hold requires increasing its size, leading to a larger machine tool footprint and lower space utilization. For example, gantry-type tool magazines and similar types typically increase the number of layers in the magazine to accommodate more tools. This requires a motion mechanism on the machine tool to drive the spindle to retrieve the tools from the magazine. However, an empty slot needs to be left in the magazine. The motion mechanism first places the tool from the spindle into the empty slot before the spindle retrieves the tool from the magazine. This tool-changing process results in low efficiency and a long spindle travel, impacting production efficiency. Therefore, increasing the number of tools in the magazine, improving machine tool space utilization, and enhancing tool-changing efficiency are the objectives of this solution. Summary of the Invention

[0004] The open-type tool changer mechanism for machining centers provided by this invention forms an automated tool changing process, including tool ejection, clamping, extraction, rotation, insertion, and storage. It enables direct exchange between tools on the spindle and those in the tool magazine. During the tool changing process, the spindle only needs to move up and down, resulting in a short stroke, high tool changing efficiency, and a high level of automation. The tool magazine is located above the spindle and its shape can be designed according to the required number of tools, increasing the tool storage capacity while reducing the magazine's volume and improving machine tool space utilization. This invention also provides a tool changing method for the open-type tool changer mechanism in machining centers.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] The utility model discloses a machining center open tool changing mechanism, including frame, the frame is equipped with tool magazine, the main shaft of being equipped with in tool magazine below and can be clamped tool, the main shaft guide rail of driving main shaft vertical motion, the tool changing arm for exchanging main shaft with the tool on tool magazine and control system, the action of tool magazine, main shaft guide rail and tool changing arm is controlled uniformly by control system, and tool changing arm is arranged in parallel with main shaft and is located in the front of tool magazine and main shaft, and its characterized in that:

[0007] Tool magazine includes the tool magazine stand fixed on the frame, the chain assembly of the tool cup that inserts the tool and can drive the tool movement and the tool lifting assembly that can lift along the vertical alignment with the main shaft and can be lifted vertically, and the chain assembly of the tool cup and the tool lifting assembly are equipped on the tool magazine stand, and the tool changing opening that is opened with the tool lifting assembly is matched on the chain assembly of the tool cup, and the tool that moves to the tool changing opening enters the tool lifting assembly,

[0008] The tool changing arm includes the drive box, the arm shaft that is transmission connected with the drive box and the tool changing holding piece equipped on the front end of arm shaft, and the arm shaft is arranged in the front of tool magazine and rotates and telescopes with the transmission of drive box, and the tool changing holding piece stretches into the tool changing opening between main shaft with the forward extension of arm shaft, and is vertically aligned with the tool in the tool lifting assembly and the tool on main shaft, so that the tool is held in the tool changing holding piece with the movement of tool lifting assembly and main shaft.

[0009] Preferably, the chain assembly of the tool cup is equipped on the front of the tool magazine stand, including the driving gear that can be rotatably equipped on the tool magazine stand and is driven by motor, the driven gear that can be rotatably equipped on the tool magazine stand and is horizontally aligned with the driving gear, the chain that is around the driving gear and the driven gear, the tool cup that is matched with the chain and is used for inserting the tool, and the outer check ring that prevents the tool cup from falling off the chain, the chain grooves for placing the tool cup are uniformly arranged on the chain, the outer check ring is the same as the chain and is arranged on the outer periphery of the chain, and the tool cup is placed in the chain groove and moves synchronously with the chain.

[0010] Preferably, the tool changing opening is opened at the bottom of the outer check ring, and the tool lifting assembly includes the lifting cylinder equipped on the back of the tool magazine stand, the lifting plate connected with the extension end of the lifting cylinder and arranged on the back of the tool magazine stand, and the supporting holding piece equipped on the lifting plate, the tool cup moves to the tool changing opening with the chain and enters the supporting holding piece at the tail end, the tool cup guide groove for guiding the lifting of the tool cup is arranged on the tool magazine stand, and the tool cup guide groove is vertically aligned below the tool changing opening.

[0011] Preferably, the lifting plate is guided by the guide rail on the back of the tool magazine stand, the tool magazine stand is provided with a through hole at the position of the lifting plate, and the supporting and clamping member is arranged in the through hole and comprises a clamping oil cylinder, a clamping part of the tool cup made of rubber and fixed on the upper end of the clamping oil cylinder, and a tool cup supporting part fixed on the middle part of the clamping oil cylinder, the tool cup supporting part is horizontally aligned with the tool changing opening, the tail end of the tool cup entering the supporting and clamping member is supported on the tool cup supporting part, and the tool cup is clamped between the clamping part of the tool cup and the tool cup supporting part with the shortening of the clamping oil cylinder.

[0012] Preferably, the driving box comprises a box body, a speed reducer motor arranged on the box body, a gear transmission assembly arranged in the box body and connected with the output shaft of the speed reducer motor, the inner end of the arm shaft is connected with the gear transmission assembly and the outer end of the arm shaft is connected with the tool changing clamping member.

[0013] Preferably, the gear transmission assembly comprises a driving bevel gear coaxially fixed with the output shaft of the speed reducer motor, a driven bevel gear engaged with the driving bevel gear, an incomplete large gear having only one-eighth of the outer periphery provided with gear teeth, a pinion cylinder matched with the incomplete large gear, the outer diameter of the incomplete large gear is larger than the outer diameter of the driven bevel gear, the incomplete large gear and the driven bevel gear are coaxially fixed through a driven shaft, the driven shaft is perpendicular to the output shaft of the speed reducer motor and parallel to the arm shaft, the driven shaft and the pinion cylinder are rotatably arranged on the box body through bearings respectively, the outer diameter of the pinion cylinder is smaller than the outer diameter of the driven bevel gear, the pinion cylinder is coaxially connected with the inner end of the arm end and arranged below the incomplete large gear, and the incomplete large gear is engaged with the pinion cylinder with the rotation of the driven bevel gear.

[0014] Preferably, the arm shaft comprises a tool changing shaft, a shaft sleeve sleeved on the tool changing shaft and fixed with the box body, the inner end of the tool changing shaft is coaxially keyed connected with the pinion cylinder in the box body, and the outer end of the tool changing shaft is connected with the tool changing clamping member, a hinge connecting rod is arranged between the driving bevel gear and the tool changing shaft, and the connecting rod drives the tool changing shaft to stretch out or retract backward with the rotation of the driving bevel gear.

[0015] Preferably, the tool changing shaft is provided with an integral limiting convex ring, the limiting convex ring is located in the box body and contacts with the box body to limit the stretching length of the tool changing shaft with the stretching out of the tool changing shaft, a cam roller protruding radially is threadedly installed on the tool changing shaft, a cam groove arranged in the axial direction and an inner concave ring groove located behind the cam groove are arranged on the inner wall of the shaft sleeve, the cam roller stretches into the cam groove to limit the rotation of the tool changing shaft with the stretching out of the tool changing shaft or separates from the cam groove and enters the inner concave ring groove to eliminate the rotation limitation of the tool changing shaft with the retraction of the tool changing shaft.

[0016] Preferably, the tool changing clamping member comprises a clamping jaw mounting plate fixed with the front end of the arm shaft through a tension sleeve and clamping jaws symmetrically arranged at both ends of the clamping jaw mounting plate, and the clamping jaw mounting plate is perpendicular to the arm shaft.

[0017] The clamping jaw comprises two oppositely arranged clamping jaw pieces, the middle part of the clamping jaw piece is hinged to a clamping jaw mounting plate, the outer ends of the two clamping jaw pieces are oppositely arranged to form a tool clamping opening corresponding to a clamping groove on the tool, the clamping jaw mounting plate is provided with an elastic pressing limiting column which can be pressed down or rebounded, the elastic pressing limiting column is clamped at the inner end of the two clamping jaw pieces to limit the opening of the tool clamping opening, the position close to the inner end of the clamping jaw piece is connected with a support spring arranged perpendicularly to the clamping jaw piece, the support spring is connected with the clamping jaw mounting plate, and the support spring supports the clamping jaw to clamp the tool when the clamping jaw clamps the tool.

[0018] The front end of the arm shaft extends from the clamping jaw bottom plate, the tool magazine stand is provided with a front end positioning hole corresponding to the front end of the arm shaft, two pressing pins are symmetrically arranged on the outer periphery of the front end positioning hole, the forward extension of the arm shaft enters the front end positioning hole, and the elastic pressing limiting column is pressed down by the pressing pin to be separated from the inner end of the clamping jaw piece.

[0019] The tool changing method of the machining center opening type tool changing mechanism has the beneficial effects that:

[0020] S1, the drive box drives the arm shaft to extend forward, so that the tool changing clamping piece extends into the space between the tool changing opening and the main shaft;

[0021] S2, the tool cup chain assembly moves the replaced tool into the tool changing opening and into the tool lifting assembly;

[0022] S3, the tool lifting assembly drives the tool to descend and clamp the tool on the tool changing clamping piece, and the main shaft guide rail drives the main shaft to ascend and clamp the tool on the main shaft;

[0023] S4, the drive box drives the arm shaft to retract backward, and the tool is separated from the tool lifting assembly and the main shaft along with the backward movement of the tool changing clamping piece;

[0024] S5, the drive box drives the arm shaft to rotate by 180 degrees, so that the two tools on the tool changing clamping piece are exchanged in position;

[0025] S6, the drive box drives the arm shaft to extend forward again, and drives the tools on the tool changing clamping piece to enter the tool lifting assembly and the main shaft respectively;

[0026] S7, the tool lifting assembly ascends to separate the tool from the tool changing clamping piece and enter the tool changing opening, and the main shaft guide rail descends to separate the tool from the tool changing clamping piece and clamp the tool on the main shaft.

[0027] The beneficial effects of the application are:

[0028] The machining center opening type tool changing mechanism of the application, the tool magazine is arranged above the main shaft, the tool changing opening is arranged on the tool cup chain assembly of the tool magazine, the required tool changing out-of-magazine station is formed, the tool moving to the tool changing opening enters the tool lifting assembly, the tool is lowered by the tool lifting assembly to realize the out-of-magazine, the tool changing arm is arranged in front of the main shaft and the tool magazine, the tool changing clamping piece rotates and stretches along with the arm shaft, the tool changing clamping piece stretches forward and stretches into the space between the tool changing opening and the main shaft, the tool lowered along with the tool lifting assembly enters the tool changing clamping piece and is clamped, the main shaft tool rising along with the main shaft guide enters the tool changing clamping piece and is clamped, the out-of-tool and the clamping tool are synchronous, the tool changing clamping piece retracts backward along with the arm shaft after clamping the tool, the tool is extracted from the tool lifting assembly and the main shaft, then the tool changing clamping piece rotates 180 degrees, the two tools on the tool changing clamping piece exchange positions, the tool changing clamping piece stretches forward after the exchange, the tool is inserted into the tool lifting assembly and the main shaft, the tool is separated from the tool changing clamping piece by the rising of the tool lifting assembly and the lowering of the main shaft, the in-magazine and the clamping on the main shaft of the tool after the exchange are realized, the automatic tool changing process from the out-of-tool, the clamping tool, the extraction tool, the rotating tool to the in-magazine is formed, the direct exchange of the tool on the main shaft and the tool in the tool magazine is realized, the main shaft only needs to rise and fall in the tool changing process, the stroke is short, the tool changing efficiency is high, the tool changing automation level is high, the tool magazine is arranged above the main shaft, the shape can be designed according to the storage quantity requirement of the tool, the tool storage quantity is increased on the basis of reducing the space volume of the tool magazine and improving the space utilization rate of the machine tool. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is a schematic diagram of the machining center opening type tool changing mechanism in the specific embodiment.

[0030] Figure 2 It is a schematic diagram of the main shaft and the main shaft guide arranged on the rack.

[0031] Figure 3 It is a schematic diagram of the tool magazine.

[0032] Figure 4 It is another schematic diagram of the tool magazine.

[0033] Figure 5 It is a back view schematic diagram of the tool magazine.

[0034] Figure 6 It is a half cut schematic diagram of the tool lifting assembly arranged on the tool magazine stand.

[0035] Figure 7 It is a schematic diagram of the tool clamping piece and the tool cup guide slot arranged on the tool magazine stand.

[0036] Figure 8 It is a schematic diagram of the tool changing arm.

[0037] Figure 9Fig. 4 is a schematic view of the tool changing arm when the box is removed.

[0038] Figure 10 Fig. 5 is a schematic view of the cam roller on the tool changing shaft and the sleeve.

[0039] Figure 11 Fig. 6 is a schematic view of the sleeve.

[0040] Figure 12 Fig. 7 is a schematic view of the tool changing holder.

[0041] Figure 13 Fig. 8 is a top view of the tool changing holder.

[0042] Figure 14 Fig. 9 is a sectional view of the tool changing holder. DETAILED DESCRIPTION

[0043] The following Figures 1-14 The embodiments of the present application are described in detail.

[0044] The open tool changing mechanism of the machining center comprises a frame 1, a tool magazine 2 mounted on the frame 1, a spindle 3 mounted below the tool magazine 2 and capable of clamping a tool, a spindle guide rail 4 for driving the spindle 3 to move vertically, a tool changing arm 5 for changing the tool on the spindle 3 and the tool magazine 2, and a control system, the actions of the tool magazine 2, the spindle guide rail 4 and the tool changing arm 5 are controlled by the control system, the tool changing arm 5 is horizontally arranged and parallel to the spindle 2 and located in front of the tool magazine 2 and the spindle 3, and characterized in that:

[0045] The tool magazine 2 comprises a tool magazine stand 6 fixed on the frame 1, a tool cup chain assembly 7 for storing and driving the tool to move, and a tool lifting assembly 8 vertically aligned with the spindle 3 and capable of lifting vertically, the tool cup chain assembly 7 and the tool lifting assembly 8 are both mounted on the tool magazine stand 6, the tool cup chain assembly 7 is provided with a tool changing opening 9 matched with the tool lifting assembly 8, and the tool moved to the tool changing opening 9 enters the tool lifting assembly 8;

[0046] The tool changing arm 5 comprises a driving box 10, an arm shaft 11 in transmission connection with the driving box 10, and a tool changing holder 12 mounted on the front end of the arm shaft 11, the arm shaft 11 is arranged in front of the tool magazine 2 and rotates and stretches with the transmission of the driving box 10, the tool changing holder 12 stretches into the space between the tool changing opening 9 and the spindle 3 with the arm shaft 11 extending forward, and is vertically aligned with the tool in the tool lifting assembly 8 and the tool on the spindle 3, so that the tool is clamped in the tool changing holder with the movement of the tool lifting assembly 8 and the spindle 3.

[0047] The machining center opening tool changing mechanism described above, the tool magazine 2 is arranged above the spindle 3, the tool changing opening 9 is opened on the tool cup chain assembly 7 of the tool magazine 2, forming the required tool changing out-of-magazine station, the tool moving to the tool changing opening 9 enters the tool lifting assembly 8, and the tool is lowered by the tool lifting assembly 8 to realize the out-of-magazine of the tool, the tool changing arm 5 is arranged in front of the spindle 3 and the tool magazine 2, wherein the tool changing clamping piece 12 rotates and stretches with the arm shaft 11, the tool changing clamping piece 12 stretches forward and stretches into between the tool changing opening 9 and the spindle 3, so that the tool descending with the tool lifting assembly 8 enters the tool changing clamping piece 12 and is clamped, and the spindle tool ascending with the spindle guide rail 4 also enters the tool changing clamping piece and is clamped, the out-of-tool and the clamping tool are synchronized to realize, after the tool changing clamping piece 12 clamps the tool, the arm shaft 11 is retracted backward, the tool is extracted from the tool lifting assembly 8 and the spindle 3 synchronously, then the tool changing clamping piece 12 is rotated by 180 degrees, so that the two tools on the tool changing clamping piece 12 are exchanged, after the exchange, the tool changing clamping piece 12 stretches forward to insert the tool into the tool lifting assembly 8 and the spindle 3, and then the tool is separated from the tool changing clamping piece 12 by the ascending of the tool lifting assembly 8 and the descending of the spindle 3, so as to realize the in-magazine and clamping of the tool after the exchange, and form the automatic tool changing process of the out-of-tool, the clamping tool, the extraction tool, the rotation tool and the insertion tool into the magazine, realize the direct exchange of the tool on the spindle 3 and the tool in the tool magazine 2, the spindle 3 only needs to ascend and descend in the tool changing process, the stroke is short, the tool changing efficiency is high, the tool changing automation level is high, the tool magazine is arranged above the spindle, and the shape can be designed according to the storage quantity requirement of the tool, so as to increase the tool storage quantity on the basis of reducing the tool magazine space volume and improving the machine tool space utilization.

[0048] The knife cup chain assembly 7 is installed on the front of the knife library stand 6, and includes a driving gear 71 rotatably installed on the knife library stand 6 and driven by a motor, a driven gear 72 rotatably installed on the knife library stand 6 and horizontally aligned with the driving gear 71, a chain 73 arranged around the driving gear 71 and the driven gear 72, a knife cup 74 matched with the chain 73 and used for storing a knife, and an outer retaining ring 75 for preventing the knife cup 74 from falling off the chain 73. The chain 73 is uniformly provided with chain grooves 76 for placing the knife cup 74. The outer retaining ring 75 is the same shape as the chain 73 and is arranged on the outer periphery of the chain 73. The knife cup 74 is placed in the chain groove 76 and moves synchronously with the chain 73. As shown in the figure, the driving gear 71, the driven gear 72 and the chain 73 form a knife transmission chain in the shape of a waist hole. The chain 73 is provided with chain grooves 76 for placing the knife cup 74. The outer retaining ring 75 is arranged outside the chain 73. The knife cup 74 stores a knife. The knife cup 74 can move with the chain 73 and will not fall out of the chain groove 76 under the limitation of the outer retaining ring 75. The knife transmission chain in the shape of a waist hole increases the number of knives stored while reducing the space volume of the knife library 2, improving the space utilization of the machine tool. The knife lifting assembly 8 is matched with the knife changing opening 9. When the knife moves to the knife changing opening 9, it is supported by the knife lifting assembly 8. The knife is pushed into the knife clamping member 12 while descending out of the library with the knife lifting assembly 8. The out-of-knife and clamping are realized synchronously.

[0049] The tool changing opening 9 is arranged at the bottom of the outer retaining ring 75, the tool lifting assembly 8 is arranged on the tool magazine stand 6 and matched with the tool changing opening 9, the tool cup 74 separated from the outer retaining ring 75 is supported by the supporting and clamping part 83 when moving to the tool changing opening 9, the tool cup 74 is prevented from directly falling when moving to the tool changing opening 9, the lifting oil cylinder 81 is elongated to push the lifting plate 82 to descend, the supporting and clamping part 83 drives the tool cup 74 to descend synchronously in the tool cup guide groove 60, the tool stored in the tool cup 74 is moved to the tool changing clamping part 12, the lifting oil cylinder 81 is retracted to drive the supporting and clamping part 83 to ascend, the tool cup 74 is lifted along the tool cup guide groove 60 and passes through the tool changing opening 9 to be lifted to the chain groove 76, the tool cup 74 is moved to be separated from the tool lifting assembly 8 when the chain 73 is moved again and is pushed by the chain groove 76, the tool stored in the tool cup 74 is moved to the tool magazine, the tool lifting assembly 8 supports the tool cup, the outer retaining ring 75 and the tool lifting assembly 8 support the tool cup 74 on the whole chain 73, the tool lifting assembly 8 can drive the tool cup 74 to ascend and descend, the tool cup guide groove 60 guides the tool cup 74 to store and take out, the tool magazine has compact structure, small space volume, large number of stored tools, can effectively ensure the smooth storing and taking out of the tools and prevent the tools from being inclined and loosened and falling during the storing and taking out.

[0050] The lifting plate 82 is guided by the guide rail on the back of the tool magazine vertical frame 6. The tool magazine vertical frame 6 is provided with a through hole 61 at the position of the lifting plate 82. The supporting and clamping part 83 is arranged in the through hole 61. The supporting and clamping part 83 comprises a clamping oil cylinder 84, a tool cup clamping part 85 made of rubber and fixed on the upper end of the clamping oil cylinder 84, and a tool cup supporting part 86 fixed on the middle part of the clamping oil cylinder 84. The tool cup supporting part 86 is horizontally aligned with the tool changing opening 9. The tail end of the tool cup entering the supporting and clamping part 83 is supported on the tool cup supporting part 86 and is clamped between the tool cup clamping part 85 and the tool cup supporting part 86 when the clamping oil cylinder 84 is shortened. The clamping oil cylinder 84 is fixed on the lifting plate 82 and located in the through hole 61. As shown in the drawings, the tool cup supporting part 86 extends forward from the through hole 61. The tool cup clamping part 85 is arranged above the tool cup supporting part 86. When the tool cup 74 moves to the tool changing opening 9, the tail end of the tool cup 74 is supported on the tool cup supporting part 86 and is clamped between the tool cup clamping part 85 and the tool cup supporting part 86 when the tool cup clamping part 85 is lowered. This can effectively prevent the tool cup from falling off and tilting forward, so that the posture of the tool cup does not change. When the lifting oil cylinder 87 is elongated, the lifting plate 82 is pushed to move downward along the guide rail, so that the supporting and clamping part 83 clamps the tool cup 74 to move downward synchronously. The supporting and clamping part 83 effectively clamps the tool cup and can drive the tool cup to move upward and downward synchronously, so as to ensure that the tool is smoothly taken out of the tool magazine and put into the tool magazine. The supporting and clamping part 83 is a clamping part of the tool cup on the tool taking-out station. The tool cup 74 is clamped when the tool reaches the taking-out station. When the tool is pulled out backward by the tool changing clamping part 12, the tool cup 74 remains stationary and does not move backward with the tool. When the tool changing clamping part 12 is retracted backward, the tool and the tool cup 74 are effectively separated. The reliability and operation stability of the whole tool changing mechanism are improved.

[0051] The driving box 10 comprises a box body 13, a speed reducer motor 14 arranged on the box body 13, and a gear transmission assembly 15 arranged in the box body 13 and connected with the output shaft of the speed reducer motor. The inner end of the arm shaft 11 extends into the box body 13 and is connected with the gear transmission assembly 15. The outer end of the arm shaft 11 extends out of the box body 13 and is connected with the tool changing clamping part 12. The rotation and extension of the arm shaft 11 are driven by the speed reducer motor 14, so as to drive the tool changing clamping part 12 to extend forward, retract backward and rotate. When the tool changing clamping part 12 extends forward, it enters between the tool changing opening 8 and the main shaft 3 to clamp the tool. When the tool changing clamping part 12 retracts backward, the tool 100 is pulled out of the tool lifting assembly 9 and the main shaft 3. When the tool changing clamping part 12 rotates, the two tools clamped on the tool changing clamping part 12 are exchanged in position. When the tool changing clamping part 12 extends forward again, the exchanged tools can be inserted into the tool lifting assembly 9 and the main shaft 3.

[0052] The gear transmission assembly 15 comprises a driving bevel gear 151 coaxially fixed with the output shaft of the speed reducer motor 14, a driven bevel gear 152 engaged with the driving bevel gear 151, an incomplete gear wheel 153 with gear on only one-eighth of the outer periphery, a pinion 154 matched with the incomplete gear wheel 153, the outer diameter of the incomplete gear wheel 153 being larger than that of the driven bevel gear 152, the incomplete gear wheel 153 and the driven bevel gear 152 being coaxially fixed through a driven shaft 155, the driven shaft 155 being perpendicular to the output shaft of the speed reducer motor 14 and parallel to the arm shaft 11, the driven shaft 155 and the pinion 154 being rotatably mounted on the box body 13 through bearings, the outer diameter of the pinion 154 being smaller than that of the driven bevel gear 152, the pinion 154 being coaxially connected with the inner end of the arm shaft 11 and arranged below the incomplete gear wheel 153, the incomplete gear wheel 153 being engaged with the pinion 154 with the rotation of the driven bevel gear 152. The output shaft of the speed reducer motor 14 drives the driving bevel gear 151 to rotate, the driving bevel gear 151 drives the driven bevel gear 152 to rotate synchronously, the driven bevel gear 152 drives the incomplete gear wheel 153 to rotate through the driven shaft 155, the half-circle gear on the incomplete gear wheel 153 is engaged with the pinion 154 after the rotation of the incomplete gear wheel 153, the pinion 154 is driven to rotate, the arm shaft 11 is driven to rotate synchronously, so that the rotation of the tool changing and holding piece 12 is realized. When the half-circle gear on the incomplete gear wheel is not engaged with the gear on the pinion 154, the arm shaft 11 is not rotated, so that the multi-step actions of the tool changing and holding piece 12 extending forward, retracting backward and rotating to extend forward again are realized. The driven shaft 154 is rotatably supported on the box body 13 through a bearing, so that the smoothness of power transmission is ensured.

[0053] The arm shaft 11 comprises a tool changing shaft 111, a shaft sleeve 112 sleeved on the tool changing shaft 111 and fixed with the box 13, the inner end of the tool changing shaft 111 extends into the box 13 and is coaxially keyed connected with the pinion cylinder 154, the outer end of the tool changing shaft 111 extends out of the shaft sleeve 112 and is connected with the tool changing holder 12, a hinged connecting rod 113 is connected between the driving bevel gear 151 and the tool changing shaft 111, the connecting rod 113 drives the tool changing shaft 111 to extend forward or retract backward along with the rotation of the driving bevel gear 151. The pinion cylinder 154 is rotatably mounted on the box 13 through a bearing and is keyed connected with the inner end of the tool changing shaft 111, the tool changing shaft 111 can axially extend and retract relative to the pinion cylinder 154 and rotates along with the rotation of the pinion cylinder 154, the pinion cylinder 154 is used to drive the tool changing shaft 111 to rotate and also used to axially support the inner end of the tool changing shaft 111. The driving bevel gear 151, the connecting rod 113 and the tool changing shaft 111 form a crank connecting rod mechanism, in the first half of the rotation of the driving bevel gear 151, the connecting rod 113 drives the tool changing shaft 111 to extend, and in the extending process, the incomplete gear 153 is not meshed with the pinion cylinder 154, so the tool changing shaft 111 does not rotate, in the second half of the rotation of the driving bevel gear 151, the connecting rod 113 pulls the tool changing shaft 111 to retract backward, and in the second half of the retracting process, the incomplete gear 153 is meshed with the pinion cylinder 154, so the tool changing shaft 111 rotates 180 degrees, the driving bevel gear 151 continues to rotate and the connecting rod 113 drives the tool changing shaft 111 to extend, so as to realize the tool changing process that the tool changing holder 13 extends forward, retracts backward, rotates 180 degrees and then extends forward again.

[0054] The limit convex ring 114 is located in the box 13 and contacts the box 10 to limit the extension length of the tool changing shaft 111 when the tool changing shaft 111 extends forward. The cam roller 115 is threadedly installed on the tool changing shaft 111 and extends outward in the radial direction. The inner wall of the shaft sleeve 112 is provided with the cam groove 116 arranged in the axial direction and the inner recess ring groove 117 located behind the cam groove 116. The cam roller 115 extends into the cam groove 116 to limit the rotation of the tool changing shaft 111 when the tool changing shaft 111 extends forward, or the cam roller 115 separates from the cam groove 116 and enters the inner recess ring groove 117 to eliminate the rotation limitation of the tool changing shaft 111 when the tool changing shaft 111 retracts backward. The shaft sleeve 112 is fixed with the box 13 and cannot rotate, and guides the extension and retraction of the tool changing shaft 11. The tool changing shaft 111 drives the tool changing holder 12 to rotate. The limit convex ring 114 limits the extension of the tool changing shaft 111. The initial position of the limit convex ring 114 is separated from the inner wall of the box and does not contact the inner wall of the box. When the limit convex ring 114 contacts the inner wall of the box 10, the tool changing shaft 111 extends to the maximum length and cannot continue to extend forward, preventing the tool changing holder 12 from extending forward beyond the limit and colliding with and pressing the tool magazine, and preventing the inner end of the tool changing shaft 111 from being separated from the pinion cylinder 154. The cam roller 115 is used to prevent the rotation of the tool changing holder 12 when extending forward. When the tool changing shaft 111 extends forward, the cam roller 115 enters the cam groove 116 to limit the rotation of the tool changing shaft 111 relative to the shaft sleeve 112, i.e., to limit the rotation of the tool changing holder 12. When the tool changing shaft 111 retracts backward, the cam roller 115 comes out of the cam groove 116 and enters the inner recess ring groove 117. The cam roller 115 does not contact the inner wall of the inner recess ring groove 117 and does not limit the rotation of the tool changing shaft 111. At this time, the tool changing shaft 111 can rotate by 180 degrees to drive the tool changing holder 12 to rotate by 180 degrees, realizing the exchange of the tool position. The cooperation of the cam roller 115, the cam groove 116 and the inner recess ring groove 117 realizes the limited rotation function that the tool changing holder 12 cannot rotate when extending forward and can rotate when retracting forward, preventing the tool changing holder 12 from rotating when extending forward and causing the tool changing holder 12 to be inclined and the tool to be unable to accurately enter the tool changing holder 12, ensuring the reliability of the tool changing holder 12 in clamping the tool.

[0055] The tool changing holder 12 includes the jaw mounting plate 121 fixed with the arm shaft 11 through the tensioning sleeve and the jaws 122 symmetrically arranged at both ends of the jaw mounting plate 121. The jaw mounting plate 121 is perpendicular to the arm shaft 11.

[0056] The clamping jaw 122 comprises two oppositely arranged clamping jaw pieces 16, the middle part of the clamping jaw pieces 16 is hinged with the clamping jaw mounting plate 121, the outer ends of the two clamping jaw pieces 16 are oppositely arranged to form a tool clamping opening 17 corresponding to the clamping groove on the tool, the clamping jaw mounting plate 121 is provided with elastic pressing limiting columns 18 which can be pressed down or rebound, the elastic pressing limiting columns 18 are clamped at the inner ends of the two clamping jaw pieces 16 to limit the opening of the tool clamping opening 17, the position close to the inner end of the clamping jaw piece 16 is connected with a supporting spring 19 arranged perpendicularly to the clamping jaw piece 16, the supporting spring 19 is connected with the clamping jaw mounting plate 121, and the supporting spring 19 supports the clamping jaw piece 16 to clamp the tool when the clamping jaw 122 clamps the tool;

[0057] The front end of the arm shaft 11 protrudes from the clamping jaw bottom plate 121, and the tool magazine stand 6 has a front end positioning hole 62 corresponding to the front end of the arm shaft 11. Two pressing pins 63 are symmetrically arranged on the outer periphery of the front end positioning hole 62. When the arm shaft 11 protrudes forward into the front end positioning hole 62, the elastic pressing limiting column 18 is pressed down by the pressing pin 63 and separated from the inner end of the clamping jaw piece 15. As shown in the figure, the clamping jaw 122 is symmetrically arranged at both ends of the clamping jaw mounting plate 121. Each clamping jaw 122 is formed by two oppositely arranged clamping jaw pieces 16. The tool clamping opening 17 is formed between the two clamping jaw pieces 16. The elastic pressing limiting column 18 is composed of a spring and a limiting column. The limiting column is clamped between the inner ends of the two clamping jaw pieces 16. When pressed, the spring compresses the limiting column to press down and separate from the clamping jaw piece 16. When the pressing force disappears, the spring pushes the limiting column to rise again and contact the inner end of the clamping jaw piece 16. When the elastic pressing limiting column 18 is not pressed, it is clamped between the two clamping jaw pieces 16. At this time, the two clamping jaw pieces 16 cannot swing outward, and the tool clamping opening 17 cannot be further expanded. The arm shaft 11 protrudes forward, and when the front end enters the positioning hole 62, the pressing pin 63 will press the elastic pressing limiting column 18 one by one, so that the two clamping jaws 122 are pressed down synchronously, and the inner end of the clamping jaw piece 16 is separated. At this time, the outward swinging of the clamping jaw piece 16 is not limited. When the tool lifting assembly 8 descends, the tool 100 in the tool cup 74 is pushed into the tool clamping opening 17. The upward movement of the main shaft guide rail 4 pushes the tool on the main shaft into the tool clamping opening 17 of the other clamping jaw 122. The tool clamping opening 17 is expanded and opened due to the entry of the tool, so that the supporting spring 19 is compressed. The elastic restoring force of the supporting spring 19 supports the clamping jaw piece 16, so that the clamping jaw piece 16 clamps the tool 100. The clamping groove corresponding to the tool clamping opening 17 is arranged on the tool 100. When the tool clamping piece 12 is retracted backward, the tool 100 is pulled out backward synchronously and separated from the tool cup 74 and the main shaft 3. When the tool clamping piece 12 is retracted backward, the front end of the arm shaft 11 is separated from the positioning hole 62, so that the elastic pressing limiting column 18 is separated from the pressing pin 63. The elastic pressing limiting column 18 is popped up and clamped between the inner ends of the two clamping jaw pieces 16 again. When the tool 100 is clamped by the tool clamping piece 12, the tool clamping opening 17 cannot be expanded and opened, effectively preventing the tool 100 from separating from the tool clamping piece 12, improving the clamping reliability of the tool clamping piece 12 to the tool during tool changing, and improving the tool changing safety.

[0058] The present application also protects a tool changing method of the opening type tool changing mechanism of the machining center, which is characterized by comprising the following steps:

[0059] S1, the drive box 10 drives the arm shaft 11 to protrude forward, so that the tool clamping piece 12 protrudes into the tool changing opening 9 between the main shaft 3;

[0060] S2, the tool cup chain assembly 7 moves the replaced tool into the tool changing opening 9 and into the tool lifting assembly 8.

[0061] S3, the tool lowering assembly 8 drives the tool to descend so that it is clamped on the tool changing clamp 12, and the spindle guide 4 drives the spindle 3 to ascend so that the tool on the spindle 3 is also clamped on the tool changing clamp 12;

[0062] S4, the drive box 10 drives the arm shaft 11 to retract backward, and the tool separates from the tool lowering assembly 8 and the spindle 3 with the backward movement of the tool changing clamp 12;

[0063] S5, the drive box 10 drives the arm shaft 11 to rotate 180 degrees, so that the two tools on the tool changing clamp 12 exchange positions;

[0064] S6, the drive box 10 drives the arm shaft 11 to extend forward again, and drives the tools on the tool changing clamp 12 to enter the tool lowering assembly 8 and the spindle 3 respectively;

[0065] S7, the tool lowering assembly 3 ascends so that the tool separates from the tool changing clamp 12 and enters the tool changing opening 9, and the spindle guide 4 descends so that the tool separates from the tool changing clamp 12 and is clamped on the spindle 3.

[0066] The above-described tool changing method realizes the tool discharge by the tool lowering assembly 8 driving the tool to descend, the tool changing clamp 12 extends forward to extend into the space between the tool changing opening 9 and the spindle 3, so that the tool descending with the tool lowering assembly 8 is clamped in the tool changing clamp 12, and the spindle tool ascending with the spindle guide 4 is also clamped in the tool changing clamp, the tool discharge and clamping are realized synchronously, the tool changing clamp 12 retracts backward with the arm shaft 11 after clamping the tool, and the tool is synchronously extracted from the tool lowering assembly 8 and the spindle 3, then the tool changing clamp 12 rotates 180 degrees, so that the two tools on the tool changing clamp 12 exchange positions, after the exchange, the tool changing clamp 12 extends forward to insert the tools into the tool lowering assembly 8 and the spindle 3, then the tool separates from the tool changing clamp 12 by the ascending of the tool lowering assembly 8 and the descending of the spindle 3, so as to realize the tool storage after the exchange and clamping on the spindle, and form the automatic tool changing process of tool discharge, tool clamping, tool extraction, tool rotation, tool insertion and tool storage, realize the direct exchange of the tool on the spindle 3 and the tool in the tool magazine 2, the spindle 3 only needs to ascend and descend in the tool changing process, the stroke is short, the tool changing efficiency is high, and the tool changing automation level is high.

[0067] The technical solutions of the embodiments of the present application are described completely in combination with the drawings, and it should be noted that the described embodiments are only a part of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the present application.

Claims

1. An open-type tool changer for a machining center, comprising a frame, a tool magazine mounted on the frame, a spindle mounted below the tool magazine for clamping tools, a spindle guide rail for driving the spindle vertically, a tool changer arm for exchanging tools between the spindle and the tool magazine, and a control system. The movements of the tool magazine, the spindle guide rail, and the tool changer arm are uniformly controlled by the control system. The tool changer arm is horizontally positioned parallel to the spindle and located in front of the tool magazine and the spindle. Its characteristic is that: The tool magazine includes a tool magazine stand fixed on the frame, a tool cup chain assembly for storing and moving tools, and a tool lifting assembly that is vertically aligned with the spindle and can be raised and lowered vertically. Both the tool cup chain assembly and the tool lifting assembly are mounted on the tool magazine stand. The tool cup chain assembly has a tool changing opening that cooperates with the tool lifting assembly. The tool that moves to the tool changing opening enters the tool lifting assembly. The tool changing arm includes a drive box, an arm shaft that is connected to the drive box, and a tool changing clamping component mounted on the front end of the arm shaft. The arm shaft is located in front of the tool magazine and rotates and extends with the drive box. The tool changing clamping component extends forward with the arm shaft and enters between the tool changing opening and the main shaft, and is vertically aligned with the tool entering the tool lifting assembly and the tool on the main shaft, so that the tool is clamped in the tool changing clamping component as the tool lifting assembly and the main shaft move. The drive box includes a housing, a geared motor mounted on the housing, a gear transmission assembly mounted in the housing and connected to the output shaft of the geared motor, and the inner end of the arm shaft extends into the housing and connects to the gear transmission assembly, while the outer end extends out of the housing and connects to the tool changer clamp. The gear transmission assembly includes a driving bevel gear fixed coaxially with the output shaft of the geared motor, a driven bevel gear meshing with the driving bevel gear, an incomplete large gear with gears on only one-eighth of its outer circumference, and a small gear cylinder that meshes with the incomplete large gear. The outer diameter of the incomplete large gear is larger than the outer diameter of the driven bevel gear. The incomplete large gear and the driven bevel gear are fixed coaxially through a driven shaft. The driven shaft is perpendicular to the output shaft of the geared motor and parallel to the arm shaft. The driven shaft and the small gear cylinder are rotatably mounted on the housing through bearings. The outer diameter of the small gear cylinder is smaller than the outer diameter of the driven bevel gear. The small gear cylinder is coaxially connected to the inner end of the arm and is located below the incomplete large gear. The incomplete large gear meshes with the small gear cylinder as the driven bevel gear rotates. The arm shaft includes a tool changing shaft and a bushing fitted on the tool changing shaft and fixed to the housing. The inner end of the tool changing shaft extends into the housing and is coaxially keyed with the small gear cylinder. The outer end extends out of the bushing and is connected to the tool changing clamp. A connecting rod is hinged between the driving bevel gear and the tool changing shaft. The connecting rod drives the tool changing shaft to extend forward or retract backward as the driving bevel gear rotates. The tool changer shaft has an integrally formed limiting protrusion ring, which is located inside the housing and contacts the housing as the tool changer shaft extends forward, limiting the extension length of the tool changer shaft. A radially protruding cam roller is threadedly installed on the tool changer shaft. A cam groove and an inner concave annular groove are formed on the inner wall of the bushing. The cam roller extends into the cam groove as the tool changer shaft extends forward, limiting the rotation of the tool changer shaft, or separates from the cam groove and enters the inner concave annular groove as the tool changer shaft retracts backward, eliminating the restriction on the rotation of the tool changer shaft. The tool changer includes a jaw mounting plate fixed to the front end of the arm shaft by a tensioning sleeve and jaws symmetrically mounted at both ends of the jaw mounting plate. The jaw mounting plate is perpendicular to the arm shaft. The gripper includes two opposing gripper plates. The middle part of the gripper plates is hinged to the gripper mounting plate. The outer ends of the two gripper plates are oppositely arranged to form a tool clamping opening corresponding to the clamping groove on the tool. The gripper mounting plate is equipped with an elastic pressing limit post that can be pressed down or rebounded. The elastic pressing limit post is clamped in the inner end of the two gripper plates to restrict the opening of the tool clamping opening. A support spring is connected to the gripper plates near the inner end and is perpendicular to the gripper plates. The support spring is connected to the gripper mounting plate and supports the gripper to clamp the tool when the gripper clamps the tool. The front end of the arm shaft extends from the gripper base plate. The tool magazine stand has a front positioning hole corresponding to the front end of the arm shaft. Two pressing pins are symmetrically arranged on the outer periphery of the front positioning hole. The arm shaft extends forward and enters the front positioning hole, so that the elastic pressing limit post is pressed down by the pressing pin and separated from the inner end of the gripper plate.

2. The open-type tool changer for machining centers according to claim 1, characterized in that: The aforementioned blade cup chain assembly is mounted on the front of the tool magazine stand and includes a drive gear rotatably mounted on the tool magazine stand and driven by a motor, a driven gear rotatably mounted on the tool magazine stand and horizontally aligned with the drive gear, a chain winding between the drive gear and the driven gear, a blade cup that cooperates with the chain for inserting and storing tools, and an outer retaining ring to prevent the blade cup from falling off the chain. Chain grooves for placing the blade cup are evenly arranged on the chain, and the outer retaining ring is the same shape as the chain and is located on the outer periphery of the chain. The blade cup is placed in the chain groove and moves synchronously with the chain.

3. The open-type tool changer for machining centers according to claim 2, characterized in that: The tool changing opening is located at the bottom of the outer retaining ring. The tool lifting assembly includes a lifting cylinder mounted on the back of the tool magazine stand, a lifting plate located on the back of the tool magazine stand and retracted to the extension end of the lifting cylinder, and a support clamping component mounted on the lifting plate. The tool cup moves with the chain to the tool changing opening and its tail end enters the support clamping component. A tool cup guide groove is provided on the tool magazine stand to guide the lifting of the tool cup. The tool cup guide groove is vertically aligned below the tool changing opening.

4. The open-type tool changer for machining centers according to claim 3, characterized in that: The lifting plate is guided and engaged with the guide rail on the back of the tool magazine stand. The tool magazine stand has a through hole at the location of the lifting plate. The supporting clamping component is set in the through hole. The supporting clamping component includes a clamping cylinder, a tool cup clamping part made of rubber fixed to the upper end of the clamping cylinder, and a tool cup support part fixed to the middle of the clamping cylinder. The tool cup support part is horizontally aligned with the tool changing opening. The tail end of the tool cup that enters the supporting clamping component is supported on the tool cup support part and is clamped between the tool cup clamping part and the tool cup support part as the clamping cylinder shortens.

5. The tool changing method of the open-type tool changing mechanism of the machining center according to any one of claims 1 to 4, characterized in that, Includes the following steps: S1, the drive arm of the drive box extends forward, so that the tool changer clamp extends into the space between the tool changer opening and the spindle; S2, the tool cup chain assembly moves the replacement tool to the tool change opening and into the tool lifting assembly; S3, the tool lifting assembly drives the tool to descend and clamp it on the tool changer clamp, while the spindle guide rail drives the spindle to rise and clamp the tool on the spindle on the tool changer clamp. S4, the drive arm of the drive box retracts backward, and the tool separates from the tool lifting assembly and the spindle as the tool changer moves backward; S5, the drive arm shaft of the drive box rotates 180 degrees, causing the two tools on the tool changer to exchange positions; S6, the drive arm shaft of the drive box extends forward again, driving the tool on the tool changer clamp to enter the tool lifting assembly and the spindle respectively; S7, the tool lifting assembly rises to separate the tool from the tool changer and enter the tool changer opening, and the spindle guide rail descends to separate the tool from the tool changer and clamp it onto the spindle.

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