CN109513991B

CN109513991B - Connecting rod mechanism of machine tool turnover device and machine tool

Info

Publication number: CN109513991B
Application number: CN201811357328.3A
Authority: CN
Inventors: 赵建华; 陈留洋; 李敢; 刘代波
Original assignee: Changsha Sisheng Intelligent Device Co ltd
Current assignee: Changsha Sisheng Intelligent Device Co ltd
Priority date: 2018-11-15
Filing date: 2018-11-15
Publication date: 2020-06-19
Anticipated expiration: 2038-11-15
Also published as: CN109513991A

Abstract

The invention provides a connecting rod mechanism for a machine tool turnover device, which comprises a connecting rod, a connecting plate, a fixed seat, a first connecting shaft and a second connecting shaft, wherein the connecting rod is fixedly connected with the connecting plate; the fixed seat is arranged at the bottom of the material receiving frame, the connecting rod is provided with a hinge hole and a first annular groove and a second annular groove which are arranged in parallel at intervals, and the connecting rod is hinged on the working table plate or the working table; the first connecting shaft and the first ring groove can slide relatively; the second connecting shaft and the second annular groove can slide relatively; when the movable end of the lifting mechanism extends in place, the connecting rod mechanism lifts the material receiving frame, and the first connecting shaft is located at one end, far away from the hinge hole, of the first ring groove; the second connecting shaft is positioned at one end of the second annular groove, which is close to the hinge hole; when the movable end of the lifting mechanism retracts to the right position, the material receiving frame is put down by the connecting rod mechanism, and the first connecting shaft is positioned at one end of the first annular groove, which is close to the hinge hole; the second connecting shaft is located the one end that hinge hole place was kept away from to the second ring groove. The invention also provides a machine tool.

Description

Connecting rod mechanism of machine tool turnover device and machine tool

Technical Field

The invention relates to the field of machine tool machining, in particular to a connecting rod mechanism for a machine tool turnover device and a machine tool.

Background

When the existing vertical broaching machine is used for feeding, a protective door on the front side of the broaching machine needs to be opened firstly, then a workpiece is manually placed on a machining position of a workbench positioned in the protective door, and after the workpiece is machined, the workpiece is manually taken down from the machining position of the workbench.

However, the broaching machine has fast processing beat and high feeding and discharging frequency, and an operator needs to stand outside a protective door of the broaching machine and stretch hands to a processing position to complete the feeding and discharging operation, so that the labor intensity of working a day is high, the hands of the operator are frequently operated on the processing position, and the operator can be injured if the operator encounters misoperation of the broaching machine. In addition, the scrap brushing disc of the cutter is arranged right above the processing station, and scrap iron and cooling water remained on the scrap brushing disc can drip on the hands of an operator, so that the hands of the operator are easily injured.

Disclosure of Invention

In view of the above, the present invention provides a link mechanism for a machine tool turning device and a machine tool, so as to solve the problems that a vertical broaching machine in the prior art is inconvenient to load and unload materials and has certain dangerousness in the process of loading and unloading materials.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

the invention provides a connecting rod mechanism for a turnover device of a machine tool, wherein the machine tool comprises a workbench, a workbench plate arranged on the workbench and the turnover device, the turnover device comprises a material receiving frame and a lifting mechanism, and the material receiving frame is connected to one end of the workbench plate in a turnover manner; the fixed end of the lifting mechanism is arranged on the workbench and is positioned below the material receiving frame, the connecting rod mechanism is positioned between the material receiving frame and the lifting mechanism and is simultaneously connected with the movable end of the lifting mechanism and the material receiving frame, and the connecting rod mechanism comprises a connecting rod, a connecting plate, a fixed seat, a first connecting shaft and a second connecting shaft;

the fixed seat is arranged at the bottom of the material receiving frame, a hinge hole and a first annular groove and a second annular groove which are arranged in parallel at intervals are formed in the connecting rod, the hinge hole is formed in one end of the connecting rod, and the connecting rod is hinged to the working table plate or the working table through the hinge hole;

the first connecting shaft is fixedly connected with the fixed seat, at least one part of the first connecting shaft is arranged in the first ring groove, and the first connecting shaft and the first ring groove can slide relatively; the second connecting shaft is fixedly connected with one end of the connecting plate, at least one part of the second connecting shaft is arranged in the second annular groove, and the second connecting shaft and the second annular groove can slide relatively; one end of the connecting plate, which is far away from the second connecting shaft, is connected with the movable end of the lifting mechanism;

when the movable end of the lifting mechanism extends to the right position, the connecting rod mechanism lifts the material receiving frame, and the first connecting shaft is located at one end, away from the hinge hole, of the first ring groove; the second connecting shaft is positioned at one end of the second annular groove close to the hinge hole;

when the movable end of the lifting mechanism retracts to the proper position, the material receiving frame is put down by the connecting rod mechanism, and the first connecting shaft is positioned at one end of the first ring groove, which is close to the hinge hole; the second connecting shaft is located at one end, far away from the hinge hole, of the second annular groove.

Further, the connecting rod comprises a hinged seat, a first rod piece and a second rod piece, wherein the first rod piece and the second rod piece are connected with the hinged seat and are arranged in parallel at intervals;

the hinge hole is arranged on the hinge seat; the first ring groove is arranged on the first rod piece, and the second ring groove is arranged on the second rod piece; the first connecting shaft penetrates through the first annular groove and is fixed on the fixed seat, and the second connecting shaft penetrates through the second annular groove and is fixed at one end of the connecting plate.

Furthermore, the number of the second rod pieces and the number of the second connecting shafts are two, and the two second rod pieces are symmetrically arranged on two sides of the first rod piece; the fixing seat comprises two first vertical plates with first mounting holes arranged at intervals, the connecting plate comprises two mounting seats arranged at intervals, and each mounting seat comprises two second vertical plates with second mounting holes arranged at intervals; the first ring groove is a through groove penetrating through the first rod piece, and the second ring groove is a through groove penetrating through the second rod piece;

the first rod piece is positioned between the two first vertical plates, and the first connecting shaft penetrates through the first mounting hole and the first annular groove; each second rod piece is located between two corresponding second vertical plates of the mounting seat, and the second connecting shaft penetrates through the second mounting hole and the second annular groove.

The invention provides a machine tool in a second aspect, which comprises a workbench, a workbench plate arranged on the workbench, a turnover device and a control system, wherein the turnover device comprises a material receiving frame, a lifting mechanism and the connecting rod mechanism;

the material receiving frame is connected to one end of the working table plate in a turnover manner; the fixed end of the lifting mechanism is arranged on the workbench and is positioned below the material receiving frame, and the connecting rod mechanism is positioned between the material receiving frame and the lifting mechanism and is simultaneously connected with the movable end of the lifting mechanism and the material receiving frame;

the control system comprises a controller and a sensing device for detecting the position of a movable end of the lifting mechanism, and the controller is electrically connected with the sensing device and the lifting mechanism; the controller controls the lifting mechanism to drive the connecting rod mechanism to move so as to lift or put down the receiving rack; when the material receiving frame is lifted, the material receiving frame is in butt joint with the working table plate.

Further, the turnover device further comprises a plurality of supporting rods, and the supporting rods are arranged on the material receiving frame at intervals in parallel.

Furthermore, the turnover device also comprises two limiting blocks which are respectively arranged at two sides of the material receiving frame and close to the working table plate, and the two limiting blocks protrude out of the upper end surface of the material receiving frame and extend towards one side where the working table plate is located so as to form a step surface which can be abutted against the working table plate;

when the material receiving frame is lifted to the right position, the step surface is abutted against the working table plate.

Further, the sensing device comprises a sensor and a sensing body;

the sensing body is arranged on the movable end of the lifting mechanism, the sensor is arranged on the workbench and close to the sensing body, and the sensor is used for detecting the sensing body so as to judge whether the material receiving frame is lifted in place and/or put down in place.

Furthermore, the sensing body is an induction support, the sensor comprises two proximity switches, one proximity switch detects the induction support when the material receiving frame is lifted to the right position, and the other proximity switch detects the induction support when the material receiving frame is put down to the right position.

Further, the machine tool also comprises two guide rails symmetrically arranged on the working table plate and sliding plates capable of sliding on the two guide rails; one end of each of the two guide rails is aligned with one end, provided with the material receiving frame, of the working table plate.

Further, the machine tool is a vertical broaching machine.

The invention provides a connecting rod mechanism for a machine tool turnover device and a machine tool, wherein the turnover device with the connecting rod mechanism is arranged at one end of a working table plate of the machine tool, and a material receiving frame can be stably turned over under the condition of only arranging one connecting rod and one lifting mechanism, so that an operator can complete feeding and discharging operations on the material receiving frame extending out of a protective door without stretching a handle into a processing station of a workpiece and only standing outside the protective door, thereby not only reducing the labor intensity of the operator, but also avoiding the misoperation of the machine tool or the injury of scrap iron, cooling water and the like remained on the machine tool to the operator, and effectively protecting the personal safety of the operator while improving the production efficiency.

Drawings

Fig. 1 is a schematic view of a connection relationship between a work table and a turnover device of a machine tool according to a first embodiment of the present invention, wherein a material receiving rack is in a lowered state;

FIG. 2 is an enlarged view of a portion of FIG. 1 at A;

FIG. 3 is a schematic bottom view of the work table and the turnover device of FIG. 1 with the receiving rack in a lowered position and the support bar omitted to show the linkage;

fig. 4 is a schematic bottom structure view of the work table and the turnover device in fig. 1, wherein the receiving rack is in a lifted state;

FIG. 5 is an exploded view of the linkage mechanism of FIG. 1;

FIG. 6 is a front view of the flipping mechanism of FIG. 1 in a lowered position;

FIG. 7 is a left side view of FIG. 3;

FIG. 8 is a front view of the flipping mechanism of FIG. 1 in a raised position;

fig. 9 is a left side view of fig. 8.

Reference numerals: a turning device 100; a work table 200; a work board 300; a slide plate 400; a guide rail 500; a control system 600; a material receiving frame 1; a lifting mechanism 2; a link mechanism 3; a connecting rod 31; a first pin 311; a first ring groove 3111; a second rod 312; a second annular groove 3121; a hinge base 313; a hinge hole 3131; a connecting plate 32; a mount 321; second riser 3211; a second mounting hole 32111; a fixed base 33; a first riser 331; a first mounting hole 3311; the first connecting shaft 34; a second connecting shaft 35; an induction device 4; a sensor 41; a sensing body 42; a support bar 5; a limiting block 6; a step surface 61.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

In the description of the present invention, the "up", "down", "front", "back", "left", "right" orientation or positional relationship is based on the normal use state of the turning device, such as the orientation or positional relationship shown in fig. 1, wherein "bottom" refers to the "down" direction. It is to be understood that such directional terms are merely used to facilitate describing the invention and to simplify the description, and are not intended to indicate or imply that the device or element so referred to must be constructed and operated in a particular orientation and therefore should not be considered as limiting the invention.

Examples

An embodiment of the present invention provides a machine tool, as shown in fig. 1 and 3 to 4, including a table 200, a table plate 300, a turnover device 100, and a control system 600, wherein the table plate 300 is mounted on the table 200. The turning device 100 comprises a material receiving frame 1, a link mechanism 3 and a lifting mechanism 2, wherein the material receiving frame 1 is connected to one end of the work table plate 300 in a turnover mode, the fixed end of the lifting mechanism 2 is arranged on the work table plate 300 and located below the material receiving frame 1, the link mechanism 3 is located between the material receiving frame 1 and the lifting mechanism 2, the link mechanism 3 is simultaneously connected with the movable end of the lifting mechanism 2 and the material receiving frame 1, the control system 600 comprises a controller (not shown) and a sensing device 4 for detecting the position of the movable end of the lifting mechanism 2, and the controller is electrically connected with the sensing device 4 and the lifting mechanism 2; the controller controls the lifting mechanism 2 to drive the connecting rod mechanism 3 to move so as to lift or put down the material receiving rack 1; when the material receiving frame 1 is lifted, the material receiving frame 1 is butted with the workbench plate 300. The purpose of the sensing device 4 is to ensure that some machine tools are provided with a protective door (not shown) in order to ensure safety, and the material receiving frame 1 of the embodiment is actually connected to one end of the work table board 300 close to the protective door, and when the material receiving frame 1 is lifted to a proper position, the material receiving frame 1 can extend out of the protective door, so that an operator can stand outside the protective door to realize loading and unloading operations on the material receiving frame 1 extending out of the protective door without extending hands into a processing position of a workpiece, while some machine tools, such as a vertical broaching machine, can move up and down in the vertical direction during processing of the workpiece, so that, in order to prevent the workpiece from being processed, the material receiving frame 1 extending out of the protective door collides with the protective door, and before the workpiece is processed, the material receiving frame 1 must be ensured to be put down, and the sensing device 4 can be arranged to ensure that the control system 600 of the machine tool can sense whether the material receiving frame 1 is lifted or put down, so that the control system 600 controls other components on the machine tool to perform the next operation. The fixed end in this embodiment is the end of the lifting mechanism 2 that is always kept unchanged in position and cannot move relative to other structures of the machine tool, and the movable end refers to the end of the lifting mechanism 2 that can drive the link mechanism 3 to move by extending or retracting.

Further, as shown in fig. 3-5, 7 and 9, the link mechanism 3 includes a link 31, a connecting plate 32, a fixing seat 33, a first connecting shaft 34 and a second connecting shaft 35, the fixing seat 33 is disposed at the bottom of the material receiving frame 1, the link 31 is provided with a hinge hole 3131 and first and

second ring grooves

3111 and 3121 disposed in parallel at intervals, the hinge hole 3131 is disposed at one end of the link 31, and the link 31 is hinged on the work platen 300 through the hinge hole 3131; the first connecting shaft 34 is fixedly connected with the fixing seat 33, at least a part of the first connecting shaft 34 is disposed in the first ring groove 3111, and the first connecting shaft 34 and the first ring groove 3111 can slide relatively; the second connecting shaft 35 is fixedly connected with one end of the connecting plate 32, at least one part of the second connecting shaft 35 is arranged in the second annular groove 3121, and the second connecting shaft 35 and the second annular groove 3121 can slide relatively; one end of the connecting plate 32 far away from the second connecting shaft 35 is connected with the movable end of the lifting mechanism 2; when the movable end of the lifting mechanism 2 extends to a proper position, the link mechanism 3 lifts the material receiving frame 1, the first connecting shaft 34 is located at an end of the first ring groove 3111 away from the hinge hole 3131, and the second connecting shaft 35 is located at an end of the second ring groove 3121 close to the hinge hole 3131; during the downward movement of the lifting mechanism 2, the connecting plate 32 drives the connecting rod 31 to turn downward, the first connecting shaft 34 relatively slides backward with respect to the first annular groove 3111, the second connecting shaft 35 relatively slides forward with respect to the second annular groove 3121, when the movable end of the lifting mechanism 2 retracts to the right position, the connecting rod mechanism 3 puts down the material receiving rack 1, and the first connecting shaft 34 is located at the end of the first annular groove 3111 near the hinge hole 3131; the second connecting shaft 35 is located at an end of the second ring groove 3121 away from the hinge hole 3131. The relative sliding in this embodiment means that the relative position of the first connecting shaft 34 in the first ring groove 3111 can be changed, and the relative position of the second connecting shaft 35 in the second ring groove 3121 can also be changed.

Further, in the present embodiment, the link 31 includes a hinge seat 313 and first and

second levers

311 and 312 disposed in parallel at an interval, a hinge hole 3131 is disposed on the hinge seat 313, a first ring groove 3111 is disposed on the first lever 311, a second ring groove 3121 is disposed on the second lever 312, the first connection shaft 34 passes through the first ring groove 3111, and both ends of the first connection shaft 34 are fixed on the fixing seat 33, the second connection shaft 35 passes through the second ring groove 3121, and both ends of the second connection shaft 35 are fixed on one end of the connection plate 32.

Further, as shown in fig. 5, the number of the second rod members 312 and the second connecting shaft 35 in this embodiment is two, and the two second rod members 312 are symmetrically disposed on two sides of the first rod member 311; the fixing seat 33 includes two first vertical plates 331 with first mounting holes 3311 arranged at intervals, the connecting plate 32 includes two mounting seats 321 arranged at intervals, and each mounting seat 321 includes two second vertical plates 3211 with second mounting holes 32111 arranged at intervals; the first ring groove 3111 is a through groove penetrating through the first bar 311, and the second ring groove 3121 is a through groove penetrating through the second bar 312; the first rod 311 is located between the two first vertical plates 331, and the first connecting shaft 34 passes through the first mounting hole 3311 and the first ring groove 3111; each second rod 312 is located between the two second vertical plates 3211 of the corresponding mounting seat 321, and the second connecting shaft 35 passes through the second mounting hole 32111 and the second annular groove 3121.

In other embodiments, the first ring groove 3111 and the second ring groove 3121 may also be semi-closed structures with one side closed and the other side open, correspondingly, one end of the first connecting shaft 34 is disposed in the first ring groove 3111, the other end is fixed on the fixing seat 33, one end of the second connecting shaft 35 is disposed in the second ring groove 3121, and the other end is fixed at one end of the connecting plate 32; the first link 311 and the second link 312 may not be provided, for example, a first ring groove 3111 of a semi-closed structure and a second ring groove 3121 of a semi-closed structure may be directly formed on the link 31 having only one link, the first ring groove 3111 and the second ring groove 3121 are disposed in a back-to-back manner, correspondingly, one end of the first connecting shaft 34 is disposed in the first ring groove 3111, the other end is fixed on the fixing seat 33, one end of the second connecting shaft 35 is disposed in the second ring groove 3121, and the other end is fixed at one end of the connecting plate 32. In addition, the link 31 having only one rod may not be provided with the hinge seat 313, and for example, one end of the link 31 may be provided with a hinge hole 3131. In the present embodiment, the hinge seat 313 is hinged to the bottom of the working platform plate 300, and in other embodiments, the hinge seat 313 may be hinged to the sidewall of the working platform plate 300 or the working platform 200 as required, as long as the setting relationship between the connecting rod 31 and the fixing seat 33 described in the present embodiment is satisfied. The two second bars 312 may make the stress applied to the connecting rod 31 during the turning process more stable, in other embodiments, only one first bar 311 and one second bar 312 may be provided, or a plurality of first bars 311 and a plurality of second bars 312 may be provided. The lift mechanism 2 in this embodiment is an oil cylinder, but may be an air cylinder in other embodiments.

Generally, when a large-sized plate-shaped part is turned, in order to ensure that the turning process of the turning device is more stable, two oil cylinders or air cylinders are respectively arranged on two sides of the plate-shaped part, and the turning is realized by matching the two oil cylinders or air cylinders with corresponding connecting rods, while the turning rack 1 can be stably turned by matching one oil cylinder with one connecting rod 31, so that one oil cylinder can be saved, and the production cost can be further reduced.

Further, in order to conveniently catch a workpiece, the material receiving frame 1 is further provided with a plurality of supporting rods 5, the supporting rods 5 are arranged at intervals in parallel, and residual scrap iron and cooling water on the workpiece can fall out of the machine tool from a gap between two adjacent supporting rods 5 so as to avoid the injury of the residual scrap iron and the cooling water to an operator. Preferably, the support rod 5 is cylindrical, or at least the upper part of the support rod is semicircular in section, or at least the upper part of the support rod is a curved surface with smooth transition, the contact area with the workpiece is small, cooling water and scrap iron cannot be accumulated, and the workpiece cannot be damaged due to the fact that the surface of the support is not provided with sharp corners.

Further, as shown in fig. 1-2, two limiting blocks 6 are further disposed on two sides of the material receiving frame 1, the two limiting blocks 6 protrude from the upper end surface of the material receiving frame 1 and extend towards one side of the work platen 300 to form a step surface 61 capable of abutting against the work platen, and when the material receiving frame 1 is lifted to a proper position, the step surface 61 abuts against the work platen 300 to ensure that the support rod 5 on the material receiving frame 1 is aligned with the work platen 300.

Further, as shown in fig. 6 and 8, the sensing device 4 includes a sensor 41 and a sensing body 42; the sensing body 42 is disposed on the connection plate 32 and adjacent to the connection plate 32, and the sensor 41 determines whether the receiving frame 1 is lifted or put in place by detecting the sensing body 42. The sensing body 42 in this embodiment is an induction bracket, and the sensor 41 is two proximity switches, which are close to the induction bracket and arranged up and down in the vertical direction, and when the proximity switch located on the upper side detects the induction bracket, it indicates that the material receiving frame 1 has been lifted up to a certain position, and when the proximity switch located on the lower side detects the induction bracket, it indicates that the material receiving frame 1 has been lowered down to a certain position. In other embodiments, the sensor 41 may also be a travel switch, and correspondingly, the sensing body 42 is a bump provided on the connection plate 32 for bumping the travel switch.

Further, as shown in fig. 1, the machine tool of the present embodiment further includes a sliding plate 400 and two guide rails 500, the two guide rails 500 are symmetrically disposed on the work platen 300, one end of each of the two guide rails 500 is aligned with one end of the work platen 300 where the material receiving frame 1 is disposed, the sliding plate 400 can slide on the two guide rails 500, when a material needs to be loaded, the material receiving frame 1 is lifted to a position, the sliding plate 400 is located on the support rod 5, after an operator places a workpiece on the sliding plate 400, the sliding plate 400 slides to a processing position of the work platen 300, and at the same time, the material receiving frame 1 is placed in a position. After the workpiece is processed, the sliding plate 400 slides towards the receiving frame 1 with the workpiece, the receiving frame 1 is lifted to the right position to receive the sliding plate 400, and an operator can start a new round of feeding after taking the workpiece down.

The machine tool provided by the embodiment can be a vertical broaching machine.

The embodiment provides the link mechanism for the machine tool turnover device and the machine tool respectively, the turnover device with the link mechanism provided by the invention is arranged at one end of the working table plate of the machine tool, and the material receiving frame can be stably turned over under the condition of only arranging one connecting rod and one lifting mechanism, so that an operator can complete feeding and discharging operations on the material receiving frame extending out of a protective door without stretching a handle into a processing position of a workpiece and only standing outside the protective door, thereby not only reducing the labor intensity of the operator, but also avoiding the misoperation of the machine tool or the injury of residual scrap iron of the machine tool and cooling water to the operator, and effectively protecting the personal safety of the operator while improving the production efficiency.

The above description is only an embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of changes or substitutions within the technical scope of the present invention, and all such changes or substitutions are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.

Claims

1. A connecting rod mechanism for a machine tool turnover device comprises a protective door, a workbench plate arranged on the workbench and the turnover device, wherein the turnover device comprises a material receiving frame and a lifting mechanism, and the material receiving frame is connected to one end, close to the protective door, of the workbench plate in a turnover mode; the connecting rod mechanism is positioned between the material receiving frame and the lifting mechanism and is simultaneously connected with the movable end of the lifting mechanism and the material receiving frame;

when the movable end of the lifting mechanism extends to the proper position, the connecting rod mechanism lifts the material receiving frame so that the material receiving frame extends out of the protective door, and the first connecting shaft is located at one end, away from the hinge hole, of the first ring groove; the second connecting shaft is positioned at one end of the second annular groove close to the hinge hole;

2. The linkage mechanism according to claim 1, wherein the linkage comprises a hinge base and first and second rods connected to the hinge base and spaced in parallel;

3. The link mechanism according to claim 2, wherein the number of the second bar and the second connecting shaft is two, and the two second bars are symmetrically disposed on both sides of the first bar; the fixing seat comprises two first vertical plates with first mounting holes arranged at intervals, the connecting plate comprises two mounting seats arranged at intervals, and each mounting seat comprises two second vertical plates with second mounting holes arranged at intervals; the first ring groove is a through groove penetrating through the first rod piece, and the second ring groove is a through groove penetrating through the second rod piece;

4. A machine tool, characterized in that the machine tool comprises a protective door, a workbench plate arranged on the workbench, a turnover device and a control system, wherein the turnover device comprises a material receiving frame, a lifting mechanism and a connecting rod mechanism according to any one of claims 1 to 3;

the material receiving frame is connected to one end, close to the protective door, of the working table plate in a turnover mode; the fixed end of the lifting mechanism is arranged on the workbench and is positioned below the material receiving frame, and the connecting rod mechanism is positioned between the material receiving frame and the lifting mechanism and is simultaneously connected with the movable end of the lifting mechanism and the material receiving frame;

the control system comprises a controller and a sensing device for detecting the position of a movable end of the lifting mechanism, and the controller is electrically connected with the sensing device and the lifting mechanism; the controller controls the lifting mechanism to drive the connecting rod mechanism to move so as to lift or put down the receiving rack; when the material receiving frame is lifted, the material receiving frame is in butt joint with the working table plate, and the material receiving frame extends out of the protective door.

5. The machine tool of claim 4, wherein the turnover device further comprises a plurality of support rods, and the plurality of support rods are arranged on the material receiving frame in parallel at intervals.

6. The machine tool according to claim 5, wherein the turnover device further comprises two limiting blocks which are respectively arranged at two sides of the material receiving frame and close to the working table plate, and the two limiting blocks protrude out of the upper end surface of the material receiving frame and extend towards one side of the working table plate to form a step surface capable of abutting against the working table plate;

7. The machine tool of claim 4, wherein the sensing device comprises a sensor and a sensing body;

8. The machine tool of claim 7 wherein said sensing body is an inductive cradle and said sensor comprises two proximity switches, one of said proximity switches sensing said inductive cradle when said receiver rack is raised into position and the other of said proximity switches sensing said inductive cradle when said receiver rack is lowered into position.

9. The machine tool according to any one of claims 4 to 8, further comprising two guide rails symmetrically disposed on the table plate, and a slide plate slidable on the two guide rails; one end of each of the two guide rails is aligned with one end, provided with the material receiving frame, of the working table plate.

10. Machine tool according to claim 9, characterized in that it is a vertical bench.