KR101943634B1 - Blanking mold for punching lithium secondary battery equipped with punch cooling means - Google Patents

Abstract

The present invention relates to a blanking mold having a punch cooling means for a lithium secondary battery electrode plate and, more specifically, to a blanking mold having a punch cooling means, comprising: an upper mold and a lower mold arranged on an upper side and a lower side; a lower die which is fixated on the lower mold; a punching plate which is fixated to the lower die and has a punch hole formed on one side; an upper die which is fixated to a lower side of the upper mold; a punch which is fixated to the upper die; a punch holder which is arranged under the upper die to be separated from the upper die and has an upper through-hole penetrated by the punch; a stripper which is fixated to a lower side of the punch holder and has a lower through-hole penetrated by the punch; and a plurality of main guide posts which are arranged between the upper and lower molds and the guide elevation of the upper mold. The blanking mold having a punch cooling means for a lithium secondary battery electrode plate additionally comprises the punch cooling means, which has a distribution oil flow channel in the shape of a groove formed at a certain height from a lower end portion of the upper through-hole along the inside, a plurality of upper fine through-holes formed downwards at intervals on the distribution flow channel, a refrigerant supply hole formed on an upper side of the distribution flow channel to communicate with the outside and to receive and supply a refrigerant, and a cooling flow channel formed along the inside of the upper through-hole from the refrigerant supply hole to the distribution flow channel. The blanking mold enables the refrigerant flowing through the cooling flow channel and the distribution flow channel to cool the outside of the punch inserted into the upper through-hole, and allows the refrigerant to be inserted into the lower through-hole through the upper fine through holes.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a punch cooling method for a lithium secondary battery,

The present invention relates to a punch mold for a lithium secondary battery electrode plate, and more particularly to a punch mold for cutting and punching a thin plate-like electrode plate used for manufacturing a lithium secondary battery, To a punch mold of a lithium secondary battery electrode plate provided with a cooling means.

Generally, a rechargeable secondary battery includes a nickel-cadmium battery, a nickel-metal hydride battery, a nickel-hydrogen battery, and a lithium secondary battery.

Among these, the lithium secondary battery has many advantages over other batteries, but since the reactivity of lithium is too great to solve the stability problem, it has not been commercialized, and it has been commercialized recently.

The advantages of a lithium ion secondary battery are as follows: First, since lithium metal is lighter than any other metal, energy density is very high, second is large, and third is memory effect It is possible to charge the battery even if it is charged to some extent without completely discharging it, and the power loss due to the fourth self discharge is very small.

The lithium secondary battery having such advantages is a high-voltage battery having stability because it can be rapidly charged by the intercalation reaction of lithium which allows the charging reaction of the negative electrode to be comparatively fast and exists in the state of lithium, It is mainly used in portable electronic devices such as a mobile phone or a notebook computer, and has been used in batteries for electric vehicles in recent years.

The lithium secondary battery is formed by applying a cathode active material to a positive electrode collector in the form of a metal foil and applying an anode active material to a negative electrode collector in the form of a metal foil to form a positive electrode plate and a negative electrode plate A jelly roll made by wrapping a separator between electrode plates was prepared. The prepared jelly roll was inserted into a cylindrical or rectangular metal container, filled with an electrolyte, and sealed .

The manufacturing process of the lithium secondary battery can be divided into an electrode manufacturing process and an assembling process. The electrode manufacturing process is divided into stirring, coating, drying, and compression cutting (slitting) And an electrolyte injection and sealing process.

1 is a cross-sectional view showing a state in which a conventional lithium secondary battery electrode plate is cut.

The lithium secondary battery electrode plate (1) comprises a positive electrode plate coated with a positive electrode active material on both sides of a positive electrode collector made of aluminum, a negative electrode plate coated with a negative electrode active material on both surfaces of a copper negative electrode collector, A separator, and an anode plate, and the battery is sealed together with an electrolyte to produce a lithium secondary battery.

However, when the electrode plate (1) continuously supplied is cut to an appropriate length or a part is cut, an electrode plate punching die is used.

The pole plate punching mold is a pressing mold. When a strap-shaped pole plate is continuously inserted between the upper and lower molds, the pole plate is cut while the punch p provided on the upper mold is lowered.

However, since the thickness of the electrode plate is very thin, the clearance between the punch (p) and the punch hole (h) must be maintained at zero (0) at all times to be precisely cut at once.

Since the clearance between the punch and the punch hole must be minimized, the punch causes frictional heat due to the repeated mutual friction between the punch and the punch hole. This not only leads to deformation of the punch but also causes thermal deformation There is a problem of pushing and sticking. Therefore, a cooling device for cooling the punch to a predetermined temperature or lower during operation is required.

- Korean Registered Patent No. 10-1691937 (Dec. 27, 2016) "Cutting device for battery pole plate flowing between spaced molds" - Korean Registered Patent No. 10-1737790 (May 15, 2017) "A press die apparatus for simultaneously processing a plurality of battery pole plates for a hybrid vehicle" - Korean Registered Patent No. 10-0534762 (December 1, 2005) "Press Mold with Cooling Device" - Korean Registered Patent No. 10-1503919 (March 31, 2015) "Cooling Apparatus for Progressive Mold"

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a punch for cutting or punching a lithium secondary battery electrode plate, The present invention also provides a punch cooling means capable of performing a punch cooling operation.

According to another aspect of the present invention, there is provided a punch cooling apparatus for a lithium secondary battery, including: a lower mold having upper and lower molds, upper and lower dies, A punching plate fixed to the lower die and formed with a punch hole, an upper die fixed to the lower surface of the upper die, a punch fixed to the upper die, and an upper penetrating hole spaced below the upper die, A plurality of punch holders, a stripper fixed to a lower surface of the punch holder and having a lower through hole through which the punch passes, and a plurality of main guide posts provided to guide upward and downward movement of the upper mold, And a second through hole having a concave shape at a predetermined height from a lower end of the upper through hole, And a plurality of upper fine holes are formed downwardly at predetermined intervals on the distribution flow path. A refrigerant supply hole communicating with the outside to supply the refrigerant is formed on the upper side of the distribution flow path, A cooling passage is formed along the inner surface of the upper through hole from the hole to the distribution passage so that the coolant flowing through the cooling passage and the distribution passage cools the outer surface of the punch inserted into the upper through hole, And a punch cooling means for allowing the punch cooling means to flow into the lower through hole.

At this time, the cooling passage may be formed in a groove shape on the inner surface of the upper through hole.

The cooling passage may be formed to be inclined downward from the coolant supply hole, and may be formed around the inner surface of the upper through hole so as to surround the outer surface of the punch at least once.

A lower end of the lower through-hole inner surface may have a step formed inwardly in close contact with the outer surface of the punch, and a lower fine hole may be formed in the step at predetermined intervals.

According to the present invention configured as described above, the outer surface of the punch can be cooled while the coolant supplied from the outside flows through the cooling passage, and the coolant flows slowly and finely through the upper fine holes to the lower through hole, Lt; / RTI >

At the same time, the refrigerant lubricates between the punch and the upper and lower through holes, thereby protecting the punch and improving the cutting efficiency.

1 is a cross-sectional view showing a state of cutting a conventional lithium secondary battery electrode plate
2 is a full perspective view showing a punch mold of a lithium secondary battery electrode plate provided with punch cooling means according to an embodiment of the present invention.
Fig. 3 is an exploded perspective view of the present invention shown in Fig. 2
Fig. 4 is a perspective view showing the punch holder of the present invention shown in Fig. 2
5 is a sectional view taken along the line AA in Fig. 4
6 is a perspective view showing the stripper of the present invention shown in Fig. 2
Fig. 7 is a cross-sectional view taken along line BB of Fig.
8 is a cross-sectional view showing a punch cooling and lubrication process according to the present invention

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

For a better understanding of the present invention, the description with reference to the drawings is not intended to limit the scope of the present invention. In the following description, a detailed description of related arts will be omitted when it is determined that the gist of the present invention may be unnecessarily blurred.

FIG. 2 is an overall perspective view showing a punch mold of a lithium secondary battery electrode plate provided with punch cooling means according to an embodiment of the present invention, and FIG. 3 is an exploded perspective view of the present invention shown in FIG.

The present invention relates to a punching die which has a pressing mold structure and which is formed into a necessary shape. The punching die, which can be cut by cutting or partially punching a strap-shaped lithium secondary battery plate itself continuously entering, The punch is cooled and lubricated by improving the structure of the punch heated by the punch, so that the stable cutting operation can be continued.

The upper die 100, the lower die 200, the lower die 210, the punching plate 220, the upper die 110, the punch 120, the punch holder 130 A stripper 140, a main guide post 300, and a punch cooling unit 500.

Specifically, a punching plate 220 having a lower die 210 coupled to and fixed to the upper surface of the lower mold 200 and a punch hole 221 passing through the upper surface of the lower die 210 is replaceable As shown in FIG.

A punch 120 protruding downward is fixed to a lower surface of the upper die 110. An upper die 110 is fixed to a lower surface of the upper die 100, A punch holder 130 is spaced apart from a lower side of the punch 110, and the punch 120 passes through the punch holder 130. A strip-shaped stripper 140 is coupled and fixed to the lower surface of the punch holder 130.

The upper mold 100 and the lower mold 200 are vertically connected by a plurality of main guide posts 300 so that the upper mold 100 is lowered while the lower mold 200 is fixed And the pole plate supplied on the punching plate 220 is cut while the punch 120 is punching.

The lower mold 200 may be a rectangular shape and corresponds to a base which supports the lowering and punching operation of the upper mold 100 and is disposed at the lower end of the lower mold 200. The lower die 200 and the punching plate 220 are mounted and supported. And the lower ends of the main guide posts 300 are coupled to the four corners.

The main guide post 300 guiding the lowering and returning of the upper mold 100 is provided with a return spring (not shown), and elastically supports the lower guide 100 to return to the original state after descending.

The punch hole 221 formed in the punching plate 220 is a hole through which the punch 120 can be inserted and formed so as to have the same cross section as a cross section to be cut by punching.

The punching plate 220 may be made of a cemented carbide material and the edge of the punching hole 221 may be formed to be angled to form a lower blade.

The upper surface of the punching plate 220 is formed to be higher than the upper surface of the lower die 210 so that the upper surface of the punching plate 220 is higher than the upper surface of the lower die 210, Respectively.

A chip discharge hole is formed in the lower die 210 and the lower die 200 so as to communicate with the punch hole 221. Preferably, the discharge hole is formed to have a larger cross-sectional area than the punch hole 221, so that the chip can be smoothly discharged. The discharge hole 211 formed in the lower die 210 has a larger sectional area than that of the punch hole 221 and the discharge hole 201 formed in the lower metal die 200 is connected to the discharge hole 201 of the lower die 210, Sectional area larger than that of the punch hole 211, so that the discharge hole may be formed in a shape extending from the punch hole 221 in cross section.

Next, the upper mold 100 may be rectangular, and the upper die 110, the punch 120, the punch holder 130, and the stripper 140 are mounted and supported on the upper side. The upper mold 100 is driven to move up and down by a separate external force.

The upper ends of the main guide posts 300 are connected to the four corners of the upper mold 100, respectively. A bushing 320 is inserted into the upper mold 100 while a guide rod 310 of the main guide post 300 is inserted and a roller bearing 330 is inserted into the bushing 320 . The roller bearing 330 may be guided in the bushing 320 while the roller bearing 330 is coupled to the outer periphery of the guide rod 310. A return spring (not shown) is provided under the guide rod 310 to elastically support the upper mold 100 and return to the original position when the lower mold 100 is lowered.

The punch 120 fixed to the lower surface of the upper die 110 simultaneously penetrates the upper through hole 131 and the lower through hole 141 formed in the punch holder 130 and the stripper 140, , So as to penetrate through the gap.

The punch holder 130 may be coupled to the stripper 140 so that the punch holder 130 is separated from the upper die 110 by a predetermined distance. And is not protruded from the lower surface of the stripper 140. That is, the lower surface of the punch 120 and the lower surface of the stripper 140 are disposed on the same plane.

When the upper mold 100 is lowered, the lower surface of the upper die 110 is closely attached to the punch holder 130 so that the punch holder 130 is pushed down and the stripper 140 descends, Press to fix. At this time, the punch 120 protrudes through the lower through hole 141 to the lower side of the stripper 140, and is inserted into the punch hole 221 to cut and cut the electrode plate. At this time, the projection height of the punch 120 will be the same as the distance between the punch holder 130 and the upper die 110.

Preferably, a plurality of sub-guide posts 400 may be further provided between the punch holder 130 and the lower die 210. The punch holder 130 is resiliently supported by the sub guide post 400 to guide the punch holder 130 to descend accurately and return to the punch holder 130.

The sub guide post 400 may also include a guide rod 410 and a bushing 420.

Importantly, the cross-sectional shape and sectional area of the punch 120 are the same so that the punch 120 can be inserted into the punch hole 221 without clearance. That is, a cutting operation is performed such that the lower blade formed in the punch hole 221 and the upper blade of the punch 120 are in close contact with each other without clearance.

However, if repeated cutting operations are performed in a state in which the punch and the punch hole are in close contact with each other, frictional heat is generated due to mutual friction and the temperature rises.

The present invention is further characterized by a punch cooling means for preventing the rise of the frictional heat and keeping the punch and the punch hole at a predetermined temperature or less.

FIG. 4 is a perspective view showing the punch holder of the present invention shown in FIG. 2, FIG. 5 is a sectional view taken along the line AA in FIG. 4, FIG. 6 is a perspective view showing the stripper of the present invention shown in FIG. Fig. 5 (b) is a developed view of the inner surface of the upper through-hole opened.

The punch cooling means 500 includes a distribution passage 510 formed on the inner surface of the upper through hole 131 of the punch holder 130, an upper fine hole 520, a coolant supply hole 530, 140 formed on the inner surface of the lower through hole 141 and the lower fine hole 560. [

First, a coolant supply hole 530 is formed on the inner surface of the upper through hole 131. The coolant supply hole 530 communicates the outer surface of the punch holder 130 with the inner surface of the punch holder 130 to supply the coolant into the upper through hole 131 from the outside.

At the lower side of the coolant supply hole 530, specifically, at the lower end of the upper through hole 131, a distribution flow path 510 is formed.

The distribution flow path 510 is a groove-shaped flow path formed at a predetermined height from the lower end of the inner surface of the upper through hole 131. In other words, the upper through-hole 131 has a concave recess shape on the inner surface of the upper through-hole 131 and is formed continuously along the inner surface of the upper through-hole 131.

As shown in the figure, the upper through hole 131 may have a rectangular cross section similar to the cross section of the punch 120, but may correspond to the shape of the punch 120, and thus may be circular, semicircular or polygonal.

In the present invention, the upper through-hole 131 having a rectangular cross-section is described as an example. Since the upper through-hole 131 has four inner surfaces, the distribution flow path 510 is horizontally formed on all four inner surfaces Each being formed at the same height from the bottom. Therefore, the refrigerant impregnated in the distribution flow path 510 may have the same water level.

A plurality of upper fine holes 520 are formed on the distribution flow path 510.

As shown in the drawing, the upper fine holes 520 are formed at a predetermined interval on the bottom of the distribution flow path 510, so that refrigerant impregnated in the distribution flow path 510 flows downward Feed a little.

At this time, the upper micro-holes 520 may have a semicircular or V-shaped groove shape opening inward.

A cooling passage 540 is formed to connect the refrigerant supply hole 530 and the distribution passage 510 to allow the refrigerant supplied to the refrigerant supply hole 530 to reach the distribution passage 510.

The cooling channel 540 is a channel formed continuously along the inner surface of the upper through hole 131 and having a groove shape.

5 (b), the cooling passage 540 communicates with the coolant supply hole 530 and extends downward along the inner surface of the upper through hole 131. The upper through hole If the inner pipe 131 has a rectangular cross section, it is formed so as to pass through all four inner surfaces and then communicates with the distribution passage 510.

The cooling passage 540 is disposed so as to be in contact with the outer surface of the punch 120 inserted in the upper through hole 131. The coolant flowing into the cooling passage 540 flows through the punch 120, Cooling and lubrication are performed. That is, the cooling passage 540 spirally covers the outer surface of the punch 120.

The refrigerant gradually flows down the cooling passage 540 and flows into the distribution passage 510 and flows into the lower through hole 141 of the lower stripper 140 through the upper micro- do.

For reference, the inner diameter of the upper micro-aperture 520 is preferably formed finely. If the inner diameter of the upper micro-hole 520 is too large, the refrigerant can escape at a high speed. Therefore, the inner diameter of the upper micro-hole 520 should be appropriately selected according to the kind of the refrigerant.

When the oil is used as the refrigerant, the inner diameter of the upper fine hole 520 may be determined so that the oil may be finely discharged little by little in consideration of the viscosity of the oil.

In addition, the distribution channel 510 may be formed to surround the outer surface of the punch 120 once, but the present invention is not limited thereto, and the inclination of the distribution channel 510 can be made more gentle, Of course, it can be wrapped more than once. Therefore, the cooling efficiency can be improved.

A step 550 may protrude inward from the lower end of the lower through hole 141 of the stripper 140 and a plurality of lower fine holes 560 may be formed in the step 550.

The stepped portion 550 is formed to be stepped from the inner surface of the lower through hole 141. Since the stepped portion 550 is formed horizontally along the inner surface, the stepped portion 550 is in close contact with the outer surface of the inserted punch 120.

A gap corresponding to the width of the step 550 is formed between the inner surface of the lower through hole 141 and the punch 120 except for the step 550, ).

The lower micro-hole 560 may have a semicircular or V-shaped groove that is opened inward on the step 550, and the inner diameter of the lower micro-hole 560 may be an inner diameter of the upper micro- So that the refrigerant is finely discharged little by little.

Hereinafter, the punch cooling process according to the present invention will be described with reference to FIG. 8 is a cross-sectional view showing a punch cooling and lubrication process according to the present invention.

And a coolant such as oil is injected through the coolant supply hole 530.

The coolant injected into the coolant supply hole 530 is gradually lowered by the gravity along the inclined cooling passage 540. The coolant injected into the coolant supply hole 530 is discharged to the outer surface of the punch 120 contacting the inner surface of the upper through hole 131 So that the punch 120 is cooled and lubricated.

The refrigerant that has passed through the cooling passage 540 is permeated and filled into the distribution passage 510 and flows into the lower through hole 141 through the upper fine holes 520.

The refrigerant flowing into the lower through-hole 141 of the stripper 140 is filled in the gap between the punch and the lower through-hole 141 to cool and lubricate the punch 120.

And is slightly ejected slightly downward through the lower fine holes 560.

The refrigerant of the present invention has been described above as being able to simultaneously perform lubrication by using lubricating oil or the like. That is, the refrigerant that can be lubricated between the punch 120, the upper through hole 131 and the lower through hole 141 and discharged through the lower fine hole 560 is punched by the punch 120 Thereby enabling lubrication with the punch hole 221. [

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention may be embodied in many other specific forms without departing from the spirit or essential characteristics thereof. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by the scope of the appended claims, as well as the appended claims.

100: upper mold 110: upper die
120: Punch 130: Punch holder
131: upper through hole 140: stripper
141: Lower through hole
200: lower mold 201: discharge hole
210: Lower die 211: Discharge hole
220: Punching plate 221: Punch hole
300: main guide post 310: guide rod
320: Bushing 330: Roller bearing
400: sub-guide post
410: guide rod 420: bushing
500: Punch cooling means 510: Distribution channel
520: upper fine hole 530: coolant supply hole
540: cooling channel 550: step
560: Lower fine aperture

Claims (4)

A lower die fixed to the lower die, a punching plate fixed to the lower die and having a punch hole formed at one side thereof, an upper die fixed to the lower surface of the upper die, A punch holder fixed to a lower surface of the punch holder and provided with a lower through hole through which the punch penetrates, a punch holder fixed to the lower die of the punch holder and having an upper through- And a main guide post provided between the upper mold and the lower mold for guiding the lifting and lowering of the upper mold, the punch mold comprising:
And a plurality of upper fine holes are formed downward at a predetermined interval on the distribution flow path. The upper side of the distribution flow path is communicated with the outside, And a cooling channel is formed along the inner surface of the upper through-hole from the coolant supply hole to the distribution channel,
Further comprising punch cooling means for cooling and lubricating the outer surface of the punch inserted into the upper through hole and allowing the coolant flowing through the cooling passage and the distribution passage to flow into the lower through hole through the upper fine hole. Punch mold of lithium secondary battery electrode plate equipped with cooling means. The method according to claim 1,
Wherein the cooling passage is formed in a groove shape on the inner surface of the upper through hole. 3. The method of claim 2,
Wherein the cooling channel is inclined downward from the coolant supply hole,
Wherein the punch cooling means is formed so as to surround the inner surface of the upper through hole so as to surround the outer surface of the punch at least once. 4. The method according to any one of claims 1 to 3,
Wherein a lower end of the inner surface of the lower through hole is formed with a step formed inwardly in close contact with the outer surface of the punch and a lower fine hole is formed at a predetermined interval in the step, mold.

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