Background
The press is a simple name of a press, a hydraulic press and an oil press, and the press refers to a forming machine for forming industrial products through pressure, generally adopts a hydraulic oil cylinder, and is also called as the oil press.
The locking device of the domestic press mostly adopts a sectional type and upper stop locking mode to lock a pull rod and a slide block in the press, is not flexible enough in the actual use process, and can not be actively locked under abnormal conditions such as power failure or oil failure, and has potential safety hazards. The foreign press is provided with a whole-course locking device, but the inclined wedge locking principle and the external installation mode are adopted, so that the occupied space of the press can be increased.
Disclosure of Invention
The invention aims to provide a built-in whole-course locking device of a press, which aims to solve the problems that the whole-course locking device is not available and the external installation of the locking device occupies the external space in the prior art.
In order to achieve the purpose, the technical scheme of the invention is as follows: a built-in whole-course locking device of a press comprises a rack assembly, a double-head locking oil cylinder and two groups of locking units, wherein the rack assembly is fixed in the press, and the center of the rack assembly is provided with a through hole for a pull rod in the press to pass through; the two groups of locking units are positioned on two sides of the pull rod; the double-end locking oil cylinder is fixed on the frame assembly, and piston rods on two sides of the double-end locking oil cylinder are respectively used for driving the locking unit to lock or unlock a pull rod in the press.
Furthermore, each group of locking units comprises an elastic part, a connecting rod assembly, a chuck assembly and an eccentric rotating shaft, wherein the elastic part is positioned in a rod cavity of the double-head locking oil cylinder, the chuck assembly is provided with a central shaft hole, the eccentric rotating shaft is fixed in the central shaft hole, the rack assembly is provided with a mounting hole, and the eccentric rotating shaft is rotatably connected in the mounting hole; one side of the connecting rod assembly is hinged with a piston rod of the double-end locking oil cylinder, and the other side of the connecting rod assembly is fixed with the eccentric rotating shaft; the protruding side of the eccentric rotating shaft enables the chuck assembly to lock the pull rod, and the other side of the eccentric rotating shaft enables the chuck assembly and the pull rod to unlock.
Furthermore, one side of the chuck assembly, which is used for locking the pull rod, is provided with a groove, and the groove can hold the pull rod.
Further, the section of the chuck assembly is triangular.
Further, a friction gasket is arranged in the groove.
Further, the eccentric rotating shaft and the connecting rod assembly are fixed through a conical expansion sleeve.
Further, the elastic member is a disc spring.
The working principle of the technical scheme is as follows: under the normal state, the disc spring in the double-head locking oil cylinder can pull the piston rod to the central position, so that the piston rod drives the eccentric rotating shaft to rotate towards the central shaft through the connecting rod assembly under the elastic force action of the disc spring, and the amplified clamping force acts on the outer surface of the pull rod through the chuck assembly, so that the pull rod is embraced by friction force, and the locking purpose is achieved. When the pull rod tends to move downwards, the reverse friction force generated by the groove of the chuck assembly tries to drive the eccentric rotating shaft to rotate towards the center, so that the clamping force is continuously increased, and the heavier the slide block is in the effective action range of the clamping force, the more reliable the clamping is. When unlocking, pressure oil is introduced into the double-end locking oil cylinder to overcome elasticity, so that the piston rod extends out, the eccentric rotating shaft is driven to rotate through the connecting rod assembly, the chuck assembly is separated from the surface of the pull rod, and unlocking is completed.
The beneficial effects of this technical scheme lie in: the two groups of locking units are arranged, so that clamping is firmer. Secondly, the chuck assembly is provided with a groove, so that the stress area is increased, and the clamping force distribution is more reasonable. And the rack assembly is fixed inside the press, so that built-in installation is realized, and the external space is saved. The grooves can improve the distribution of the clamping force, so that the clamping of the chuck assembly is more reliable. The cross section of the chuck assembly is triangular, so that the stress area can be increased to the maximum extent, and the self mass is reduced. And the elastic part adopts a disc spring, so that the replacement is convenient.
Detailed Description
The following is further detailed by way of specific embodiments:
reference numerals in the drawings of the specification include: the device comprises a rack assembly 1, a double-end locking oil cylinder 2, a connecting rod assembly 3, a chuck assembly 4, an eccentric rotating shaft 5, a piston rod 6, a disc spring 7, a rod cavity 8, a pull rod 9, a sliding block 10, a central shaft hole 11, a groove 12, a friction gasket 13 and a mounting hole 14.
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The examples are substantially as shown in figures 1 to 9 of the accompanying drawings: a built-in whole-course locking device of a press comprises a rack assembly 1, a double-head locking oil cylinder 2 and two groups of locking units, wherein the rack assembly 1 is fixed in the press, and the center of the rack assembly 1 is provided with a through hole for a pull rod 9 in the press to pass through; the two groups of locking units are positioned at two sides of the pull rod 9; the double-head locking oil cylinder 2 is fixed on the frame assembly 1, and piston rods 6 on two sides of the double-head locking oil cylinder 2 are respectively used for driving the locking unit to lock or unlock a pull rod 9 in the press.
Each group of locking units comprises an elastic part, a connecting rod assembly 3, a chuck assembly 4 and an eccentric rotating shaft 5, wherein the elastic part adopts a disc spring 7, so that the replacement is more convenient, the elastic part is positioned in a rod cavity 8 of the double-head locking oil cylinder 2, the chuck assembly 4 is provided with a central shaft hole 11, the eccentric rotating shaft 5 is fixed in the central shaft hole 11, the rack assembly 1 is provided with a mounting hole 14, and the eccentric rotating shaft 5 is rotatably connected in the mounting hole 14; one side of the connecting rod assembly 3 is hinged with a piston rod 6 of the double-end locking oil cylinder 2, and the other side of the connecting rod assembly is fixed with the eccentric rotating shaft 5 through a conical expansion sleeve; the protruding side of the eccentric rotating shaft 5 enables the chuck assembly 4 to lock the pull rod 9, and the other side of the eccentric rotating shaft 5 enables the chuck assembly 4 to unlock the pull rod 9. One side of the chuck assembly 4 for locking the pull rod 9 is provided with a groove 12, and the groove 12 can hold the pull rod 9. The section of the chuck assembly 4 is triangular, a friction gasket 13 is arranged in the groove 12, and the embodiment adopts a composite material with a higher friction coefficient.
The specific implementation process is as follows:
in a normal state, the disc spring 7 in the double-head locking oil cylinder 2 pulls the piston rod 6 to the central position, so that the piston rod 6 drives the eccentric rotating shaft 5 to rotate towards the central shaft through the connecting rod assembly 3 under the elastic force action of the disc spring 7, and the amplified clamping force acts on the outer surface of the pull rod 9 through the chuck assembly 4, so that the pull rod 9 is embraced by friction force, and the locking purpose is achieved. When the pull rod 9 tends to move downwards, the reverse friction force generated by the groove 12 of the collet assembly 4 tries to drive the eccentric rotating shaft 5 to rotate towards the center, so that the clamping force is increased continuously, and the heavier the slide block 10 is in the effective action range of the clamping force, the more reliable the clamping is. During unlocking, pressure oil is introduced into the double-head locking oil cylinder 2 to overcome elasticity, so that the piston rod 6 extends out, the connecting rod assembly 3 drives the eccentric rotating shaft 5 to rotate, the chuck assembly 4 is separated from the surface of the pull rod 9, and unlocking is completed.
The following also provides a description of the parameter calculation in the device design process:
1. designing a target: the clamping force G is less than or equal to 100KN, is equal to the total weight of the sliding block and the pull rod and is also equal to the friction force F between the chuck assembly and the pull rod.
2. Determination of friction material: and the initial selection friction coefficient mu is 0.4-0.5.
3. Calculation of positive pressure W applied by the eccentric rotating shaft at the clamping position: g ═ W ═ μ, β is a design margin of clamping force, and β ═ 1.2.
4. Calculating and checking the contact area S and the specific pressure: checking according to the following formula, wherein the height H of the inner sleeve of the initial chuck assembly is 300mm, and the diameter d of the pull rod is 100 mm;
S=α*H*(πd);W/S≤p;
wherein, p is the allowable specific pressure of the friction material, alpha is the effective coefficient of the friction area, and alpha is 0.85.
5. Self-locking condition verification: checking according to the following formula, wherein the radius R of the outer ring of the initially determined eccentric rotating shaft is 80mm, the radius R of the inner ring of the eccentric rotating shaft is 46mm, the eccentricity e is 10mm, the included angle gamma between the connecting line of the two centers of the eccentric rotating shaft and the connecting line of the clamping force contact point and the center of the outer ring of the eccentric rotating shaft is 135 degrees, the friction angle is represented as psi, and mu is tan psi;
6. calculating an initial clamping force Q applied to the eccentric rotating shaft by the double-head locking oil cylinder: calculating according to the following formula, wherein the length L of the initial fixed force arm is 250 mm;
after the calculation and the verification in the steps, the values are reasonable, and the mechanism design is feasible.
It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
The foregoing is merely an example of the present invention, and common general knowledge in the field of known specific structures and characteristics is not described herein in any greater extent than that known in the art at the filing date or prior to the priority date of the application, so that those skilled in the art can now appreciate that all of the above-described techniques in this field and have the ability to apply routine experimentation before this date can be combined with one or more of the present teachings to complete and implement the present invention, and that certain typical known structures or known methods do not pose any impediments to the implementation of the present invention by those skilled in the art. It should be noted that, for those skilled in the art, without departing from the structure of the present invention, several changes and modifications can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicability of the patent. The scope of the claims of the present application shall be determined by the contents of the claims, and the description of the embodiments and the like in the specification shall be used to explain the contents of the claims.