CN109093655B

CN109093655B - Multifunctional art knife

Info

Publication number: CN109093655B
Application number: CN201811148481.5A
Authority: CN
Inventors: 张孟孟
Original assignee: Haosharp Industry Guangdong Co Ltd
Current assignee: Haosharp industry (Guangdong) Co., Ltd
Priority date: 2018-09-29
Filing date: 2018-09-29
Publication date: 2020-05-15
Anticipated expiration: 2038-09-29
Also published as: CN109093655A

Abstract

The invention belongs to the technical field of office supplies, and particularly relates to a multifunctional art knife which comprises a knife shell, a blade, a rotary spring and a knob; the back of the blade is provided with uniformly arranged convex teeth which are clamped in the gap of the rotating spring; a knob which is rotatably connected with the knife shell is arranged below the rotary spring and is designed in a disc shape; one end of the rotary spring is fixedly connected to the middle part of the knob, the right side of the knob penetrates through the cutter shell, and the side surface of the knob is designed to be rough; the knob is manually rotated in the forward direction or the reverse direction to drive the rotating spring to rotate in the forward direction or the reverse direction, the rotating spring rotates in the forward direction or the reverse direction to drive the blade to move up and down through the clamping of the convex teeth and the rotating spring, so that the blade extends out of the cutter shell or retracts into the cutter shell, and the knob with a rough surface design is more convenient to use; through manual mode, press first slider and second slider simultaneously, hit the blade from the nick below the damaged position and break, realize the reuse of blade, effectively prevent to take place the accidental injury when directly breaking off with the fingers and thumb the blade.

Description

Multifunctional art knife

Technical Field

The invention belongs to the technical field of office supplies, and particularly relates to a multifunctional art knife.

Background

The utility knife is a tool commonly used in industry and life, and is commonly used for cutting paper, leather, plastic sheets or cardboard and the like; the utility knife, also commonly known as nicking tool or wallpaper knife, usually only uses the knife tip part when the utility knife is normally used, and cutting, carving and dotting are the main functions.

Some technical solutions of art knife have appeared in the prior art, for example chinese patent with application number 2013105102098 discloses an art knife, and it includes that both ends have the open-ended and be long banding shell, set up the inside guide slot of shell sets up blade in the guide slot, be used for fixed regulation the cutter can be in gliding sliding block in the guide slot, wherein, the inboard symmetry in guide slot upper portion is provided with the location mouth of rectangle, the sliding block is provided with an adjusting part who is used for adjusting the blade business turn over, the blade passes through adjusting part with the chucking of location mouth is with loosen the realization and is in fixed and removal in the guide slot.

When the blade is pulled and pulled by the art knife, the leaf spring is not contacted with the positioning openings on the two sides, and the leaf spring and the positioning openings are not abraded after long-term use, but the traditional blade has poor toughness, the blade is easily damaged when a hard object is cut, and the blade is directly broken by hands only depending on manpower after the blade is damaged, so that the safety is low; when the utility knife is not used for a long time, the blade is easy to rust, the knife stone needs to be searched for polishing, the operation is complex, and the blade can be interrupted after being used for a long time.

Disclosure of Invention

In order to make up the defects of the prior art and solve the problems of poor toughness, low safety and easy rusting and setback of the blade, the multifunctional art designing knife provided by the invention has the advantages that the toughness of the blade is improved by arranging the knife holes uniformly on the blade, the back of the knife is provided with the convex teeth which are in a sawtooth shape, and the dual-purpose function of the art designing knife can be realized; through the setting of first whetting a knife board and second whetting a knife board, when the blade reciprocated, first whetting a knife board and second whetted a knife board and polished the blade, prevented that the blade from being washed and rusted, through cutting the device, cut after making things convenient for art designer's sword damage, avoided the direct contact blade to cause the injury to the staff.

The technical scheme adopted by the invention for solving the technical problems is as follows: the invention relates to a multifunctional art knife, which comprises a knife shell, a blade, a rotary spring and a knob; a cutter groove is formed in the cutter shell; a blade which is vertically arranged is connected in the cutter groove in a sliding manner; a braking groove is formed in the cutter shell on the right side of the cutter groove, and a vertically arranged rotating spring is arranged in the braking groove; the back of the blade is provided with uniformly arranged convex teeth which are clamped in the gap of the rotating spring; a knob which is rotatably connected with the knife shell is arranged below the rotary spring and is designed in a disc shape; one end of the rotary spring is fixedly connected to the middle part of the knob, the right side of the knob penetrates through the cutter shell, and the side surface of the knob is designed to be rough; during operation, manual forward rotation or reverse rotation knob drives the corotation of rotating spring or reversal, and the corotation of rotating spring or reversal drive the blade through dogtooth and rotating spring's block and reciprocate, make the blade stretch out in the sword shell or the indentation sword shell, the knob of matte design more facilitates the use, and can prevent in the indentation sword shell that the blade from accidentally injuring personnel.

Preferably, the two sides of the blade are respectively provided with a first fixing plate which is connected with the upper inner wall of the blade shell in a sliding manner; a first knife sharpening plate is fixed on one surface, close to the blade, of the first fixing plate, a second fixing plate is arranged on one surface, close to the blade, of the first knife sharpening plate, a second knife sharpening plate is arranged on one surface, close to the blade, of the second fixing plate, and the second knife sharpening plate is attached to the blade; first air bags which are uniformly distributed are arranged in a clearance between the first fixing plate and the inner wall of the cutter shell, the first air bags are fixedly connected between the inner wall of the cutter shell and the first fixing plate, the first air bags are in a compressed state, and third springs are arranged between every two adjacent first air bags; the third spring is fixedly connected between the inner wall of the cutter shell and the first fixing plate; when the blade grinding machine works, the first air bag and the third spring push the first fixing plate towards the blade all the time, so that the second blade grinding plate is always attached to the blade, when the blade moves up and down, the second blade grinding plate can grind the blade, the blade is sharper, the second fixing plate can be pulled away, when the second blade grinding plate is consumed, the second fixing plate is pulled away, and the first blade grinding plate is attached to the blade under the action of the third spring and the first air bag and can be continuously used.

Preferably, the knife sharpening plate is made of eighty-mesh abrasive materials, so that rust on the blade can be better ground; the first knife sharpening plate and the second knife sharpening plate are respectively and correspondingly provided with uniformly arranged open holes; the first fixing plate and the second fixing plate are both in net-shaped design; the bottom of the blade is fixedly connected with a second air bag, and the bottom of the blade shell is provided with a through hole for communicating the cutter groove with the outside; during operation, the produced abrasive dust of first whetstone and second whetstone blade of polishing passes through the trompil, netted first fixed plate and second fixed plate get into sword groove bottom, thereby discharge through the through-hole, the trompil can be to first whetstone, second whetstone and blade are cooled down simultaneously, prevent that the blade temperature is too high, lead to the life of blade to reduce, and the compression and the inflation of second gasbag, make the interior gas flow of sword groove, the blade, first whetstone and second whetstone cool down, the abrasive dust is discharged simultaneously for.

Preferably, knife holes are uniformly formed in the surface of the blade; during operation, the cutter hole can increase the toughness of the blade, and the cutter hole can play a certain role in heat dissipation when the blade cuts an object, so that the service life of the blade is prolonged.

Preferably, the convex teeth arranged on the back of the blade are in saw blade shape; the blade has a cutting function, and simultaneously, objects can be sawn through the convex teeth designed by the saw blade, so that the multifunctional knife is realized.

Preferably, the top of the knife shell is provided with a cutting device; the cutting device comprises a first sliding block, a second sliding block, a first fixing block, a second fixing block, a first spring and a second spring, wherein the first sliding block and the second sliding block are both connected to the top of the cutter shell in a sliding mode, and the first sliding block and the second sliding block are distributed at two ends of the blade; a first fixing block and a second fixing block are respectively arranged between the first sliding block and the blade and between the second sliding block and the blade; the first fixing block and the second fixing block are fixedly connected to the upper surface of the cutter shell; the side surfaces of one sides of the first sliding block and the second sliding block, which are close to the blade, are respectively and fixedly connected with a first extrusion rod and a second extrusion rod; the first extrusion rod and the second extrusion rod are both horizontally arranged, and the first extrusion rod is higher than the second extrusion rod; the surface of the first extrusion rod is sleeved with a first spring; the first spring is fixedly connected between the first sliding block and the first fixed block; the surface of the second extrusion rod is sleeved with a second spring; the second spring is fixedly connected between the second sliding block and the second fixing block, and the first extrusion rod and the second extrusion rod both penetrate through the first fixing block and the second fixing block and are not in contact with the blade; uniformly arranged nicks are carved on the surface of the blade; the during operation, the breach appears in the blade, and first slider and second slider are pressed simultaneously to the manual mode of accessible, hits the blade from the nick below the damaged position and breaks, realizes the reuse of blade, takes place the accidental injury when effectively preventing directly breaking off with the fingers and thumb the blade.

Preferably, a third air bag fixedly connected to the top of the knife shell is arranged between the first sliding block and the first fixed block, a horizontally arranged sliding groove is formed in the knife shell below the third air bag, a third sliding block is arranged in the sliding groove, the sliding groove is communicated with the third air bag, and the third sliding block is arranged in contact with the blade; when the blade fixing device works, the first sliding block slides rightwards to break the blade, the first sliding block and the first fixing block are matched to extrude the third air bag, the third air bag supplies air to the sliding groove to push the third sliding block to fix the blade, so that the blade is fixed more stably, and the blade is prevented from sliding because of unfixed stability, and the breaking position is prevented from deviating.

The invention has the following beneficial effects:

1. according to the multifunctional art knife, the rotary spring, the convex teeth and the knob are arranged, the knob is rotated forward or reversely manually to drive the rotary spring to rotate forward and reversely, the spring rotates forward and reversely to drive the blade to move up and down through the clamping of the convex teeth and the rotary spring, the blade extends out of the knife shell or retracts into the knife shell, the knob with a rough surface is more convenient to use, and the blade can be prevented from accidentally injuring people when retracted into the knife shell.

2. The multifunctional art designer knife is provided with the first air bag, the third spring, the first fixing plate, the second fixing plate, the first knife sharpening plate and the second knife sharpening plate, wherein the first fixing plate is pushed towards the direction of the blade by the first air bag and the third spring, the first fixing plate pushes the first knife sharpening plate, the second fixing plate and the second knife sharpening plate to enable the second knife sharpening plate to be always attached to the blade, the knife sharpening plate can sharpen the blade when the blade moves up and down, the second fixing plate can be drawn away, when the second knife sharpening plate is consumed, the second fixing plate is drawn away, and the first knife sharpening plate is attached to the blade under the action of the third spring and the first air bag and can be continuously used.

3. According to the multifunctional art knife, the cutting device, the third spring and the third slide block are arranged, the first slide block and the second slide block are manually pressed to break the blade from the nick below the damaged position at the same time, the blade is recycled, accidental injury caused by direct breaking of the blade is effectively prevented, the first slide block slides to the right to break the blade, the first slide block and the first fixed block are matched to extrude the third air bag, the third air bag supplies air to the sliding groove to push the third slide block to fix the blade, the blade is fixed more stably, and deviation of the breaking position caused by sliding of the blade due to unfixed blade is prevented.

Drawings

The invention will be further explained with reference to the drawings.

FIG. 1 is a front view of the present invention;

FIG. 2 is a cross-sectional view taken at A-A of FIG. 1;

FIG. 3 is an enlarged view of a portion of FIG. 2 at B;

FIG. 4 is an enlarged view of a portion of FIG. 2 at C;

in the figure: the cutter comprises a cutter shell 1, a rotating spring 11, a knob 12, a cutter groove 13, a braking groove 14, a convex tooth 15, a cutter blade 2, a first fixing plate 21, a second fixing plate 211, a first sharpening plate 22, a second sharpening plate 221, a first air bag 23, an opening 24, a second air bag 25, a through hole 26, a cutter hole 27, a nick 28, a third spring 29, a cutting device 3, a first sliding block 31, a second sliding block 32, a first fixing block 33, a second fixing block 34, a first spring 35, a second spring 36, a first extrusion rod 37, a second extrusion rod 38, a third air bag 4, a sliding groove 41 and a third sliding block 42.

Detailed Description

In order to make the technical means, the creation characteristics, the achievement purposes and the effects of the invention easy to understand, the invention is further described with the specific embodiments.

As shown in fig. 1 to 4, the utility knife of the present invention comprises a knife housing 1, a blade 2, a rotary spring 11 and a knob 12; a knife groove 13 is formed in the knife shell 1; the cutter groove 13 is internally and slidably connected with a vertically arranged blade 2; a brake groove 14 is formed in the right side of the cutter groove 13 in the cutter shell 1, and a vertically arranged rotating spring 11 is arranged in the brake groove 14; the back of the blade 2 is provided with convex teeth 15 which are uniformly arranged, and the convex teeth 15 are clamped in the gaps of the rotating spring 11; a knob 12 which is rotatably connected to the knife shell 1 is arranged below the rotary spring 11, and the knob 12 is designed in a disc shape; one end of the rotary spring 11 is fixedly connected to the middle part of the knob 12, the right side of the knob 12 penetrates through the knife shell 1, and the side surface of the knob 12 is designed to be rough; during operation, manual forward or reverse rotation knob 12 drives rotation spring 11 corotation or reversal, and rotation spring 11 corotation or reversal drive blade 2 through dogtooth 15 and rotation spring 11's block and reciprocate, make blade 2 stretch out in sword shell 1 or the indentation sword shell 1, and knob 12 of matte design facilitates the use more, and can prevent in the 2 indentation sword shells 1 of blade that blade 2 accidental injury personnel.

As an embodiment of the invention, the blade 2 is provided with a first fixing plate 21 on both sides, which is slidably connected to the upper inner wall of the blade housing 1; a first knife sharpening plate 22 is fixed on one surface of the first fixing plate 21 close to the blade 2, a second fixing plate 211 is arranged on one surface of the first knife sharpening plate 22 close to the blade 2, a second knife sharpening plate 221 is arranged on one surface of the second fixing plate 211 close to the blade 2, and the second knife sharpening plate 221 is attached to the blade 2; a gap is reserved between the first fixing plate 21 and the inner wall of the cutter shell 1, first air bags 23 which are uniformly arranged are arranged in the gap, the first air bags 23 are fixedly connected between the inner wall of the cutter shell 1 and the first fixing plate 21, the first air bags 23 are in a compressed state, and third springs 29 are arranged between every two adjacent first air bags; the third spring 29 is fixedly connected between the inner wall of the cutter housing 1 and the first fixing plate 21; when the blade sharpening device works, the first air bag 23 and the third spring 29 push the first fixing plate 21 towards the blade 2 all the time, so that the second sharpening plate 221 is attached to the blade 2 all the time, when the blade 2 moves up and down, the second sharpening plate 221 can sharpen the blade 2, the second fixing plate 211 can be drawn away, when the second sharpening plate 221 is consumed, the second fixing plate 211 is drawn away, and the first sharpening plate 22 is attached to the blade 2 under the action of the third spring 29 and the first air bag 23, so that the blade sharpening device can be used continuously.

As an embodiment of the present invention, the first sharpening plate 22 is made of eighty-mesh abrasive material, which can better remove rust on the blade; the first knife sharpening plate 22 and the second knife sharpening plate 221 are respectively and correspondingly provided with uniformly arranged open holes 24; the first fixing plate 21 and the second fixing plate 211 are both designed in a mesh shape; the bottom of the blade 2 is fixedly connected with a second air bag 25, and the bottom of the blade shell 1 is provided with a through hole 26 for communicating the blade groove 13 with the outside; in operation, the produced abrasive dust of blade 2 that first whetstone board 22 and second whetstone board 221 polish passes through trompil 24, netted first fixed plate 21 and second fixed plate 211 get into sword groove 13 bottom, thereby discharge through-hole 26, trompil 24 can be to first whetstone board 22 simultaneously, second whetstone board 221 and blade 2 cool down, prevent that blade 2 high temperature, the life that leads to blade 2 reduces, and the compression and the inflation of second gasbag 25, make the interior gas flow of sword groove 13, to blade 2, first whetstone board 22 and second whetstone board 221 cool down, the abrasive dust is discharged simultaneously has been accelerated.

As an embodiment of the present invention, the blade 2 has a uniform surface with tool holes 27; during operation, the knife hole 27 can increase the toughness of the blade 2, and the knife hole 27 can play a certain role in heat dissipation when the blade 2 cuts objects, so that the service life of the blade 2 is prolonged.

As an embodiment of the invention, the protruding teeth 15 arranged on the back of the blade 2 are of saw blade-shaped design; the blade 2 has a cutting function, and simultaneously, objects can be sawn through the convex teeth 15 designed by the saw blade, so that the multifunctional knife is realized.

As an embodiment of the invention, the top of the knife shell 1 is provided with a cutting device 3; the cutting device 3 comprises a first sliding block 31, a second sliding block 32, a first fixed block 33, a second fixed block 34, a first spring 35 and a second spring 36, wherein the first sliding block 31 and the second sliding block 32 are both connected to the top of the cutter shell 1 in a sliding manner, and the first sliding block 31 and the second sliding block 32 are distributed at two ends of the blade 2; a first fixed block 33 and a second fixed block 34 are respectively arranged between the first sliding block 31 and the blade 2 and between the second sliding block 32 and the blade 2; the first fixing block 33 and the second fixing block 34 are both fixedly connected to the upper surface of the cutter shell 1; the side surfaces of the first sliding block 31 and the second sliding block 32 close to one side of the blade 2 are fixedly connected with a first extrusion rod 37 and a second extrusion rod 38 respectively; the first extrusion rod 37 and the second extrusion rod 38 are both horizontally arranged, and the first extrusion rod 37 is higher than the second extrusion rod 38; the surface of the first extrusion rod 37 is sleeved with a first spring 35; the first spring 35 is fixedly connected between the first sliding block 31 and the first fixed block 33; the surface of the second extrusion rod 38 is sleeved with a second spring 36; the second spring 36 is fixedly connected between the second sliding block 32 and the second fixed block 34, and the first extrusion rod 37 and the second extrusion rod 38 are arranged through the first fixed block 33 and the second fixed block 34 and are not contacted with the blade 2; the surface of the blade 2 is provided with evenly distributed nicks 28; during operation, the blade 2 is notched, the first slider 31 and the second slider 32 can be pressed simultaneously in a manual mode, the blade 2 is broken from the notch 28 below the damaged position, the blade 2 is recycled, and accidental injury is effectively prevented when the blade 2 is directly broken.

As an embodiment of the present invention, a third air bag 4 fixedly connected to the top of the knife housing 1 is disposed between the first slider 31 and the first fixed block 33, a horizontally disposed sliding groove 41 is disposed in the knife housing 1 below the third air bag 4, a third slider 42 is disposed in the sliding groove 41, the sliding groove 41 is communicated with the third air bag 4, and the third slider 42 is disposed in contact with the blade 2; during operation, the first sliding block 31 slides rightwards to blow off the blade 2, the first sliding block 31 and the first fixing block 33 are matched to extrude the third air bag 4, the third air bag 4 supplies air to the sliding groove 41 to push the third sliding block 42 to fix the blade 2, so that the blade 2 is fixed more stably, and the blade 2 is prevented from sliding because of unfixed stability, and the blowing-off position is prevented from deviating.

When the tool is in work, the rotary spring 11 is driven to rotate forwards or backwards through the manual forward or reverse rotation of the knob 12, the blade 2 is driven to move up and down through the forward or reverse rotation of the rotary spring 11 through the clamping of the convex teeth 15 and the rotary spring 11, the blade 2 extends out of the tool case 1 or retracts into the tool case 1, the knob 12 with a rough surface design is more convenient to use, and the blade 2 can be prevented from accidentally injuring people when retracting into the tool case 1; the first air bag 23 and the third spring 29 push the first fixing plate 21 towards the blade 2 all the time, so that the second sharpening plate 221 is attached to the blade 2 all the time, when the blade 2 moves up and down, the second sharpening plate 221 can sharpen the blade 2, so that the blade 2 is sharper, the second fixing plate 211 can be drawn away, when the second sharpening plate 221 is consumed, the second fixing plate 211 is drawn away, and the first sharpening plate 22 is attached to the blade 2 under the action of the third spring 29 and the first air bag 23, so that the blade can be used continuously; the abrasive dust generated by the first and second

sharpening plates

22 and 221 in sharpening the blade 2 enters the bottom of the blade groove 13 through the open hole 24, the meshed first and

second fixing plates

21 and 211 to be discharged through the through hole 26, and meanwhile, the open hole 24 can cool the first sharpening plate 22, the meshed second sharpening plate 221 and the blade 2, so that the blade 2 is prevented from being too hot, the service life of the blade 2 is shortened, the gas in the blade groove 13 flows due to the compression and expansion of the second gas bag 25, the blade 2, the first sharpening plate 22 and the second sharpening plate 221 are cooled, and the abrasive dust discharge is accelerated; when the blade 2 is notched, the first slider 31 and the second slider 32 can be pressed simultaneously in a manual mode to break the blade 2 from the nick 28 below the damaged position, so that the blade 2 can be recycled, and the blade 2 can be effectively prevented from being accidentally damaged when being directly broken; the first sliding block 31 slides rightwards to break the blade 2, the first sliding block 31 and the first fixing block 33 are matched to extrude the third air bag 4, the third air bag 4 supplies air to the sliding groove 41 to push the third sliding block 42 to fix the blade 2, so that the blade 2 is fixed more stably, and the blade 2 is prevented from sliding because of unfixed stability, and the breaking position is prevented from deviating.

The foregoing illustrates and describes the principles, general features, and advantages of the present invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. A multifunctional utility knife comprises a knife shell (1), a blade (2), a rotary spring (11) and a knob (12); the method is characterized in that: a cutter groove (13) is formed in the cutter shell (1); a vertically arranged blade (2) is connected in the cutter groove (13) in a sliding manner; a brake groove (14) is formed in the right side of the cutter groove (13) in the cutter shell (1), and a vertically arranged rotating spring (11) is arranged in the brake groove (14); the back of the blade (2) is provided with convex teeth (15) which are uniformly arranged, and the convex teeth (15) are clamped in the gaps of the rotating spring (11); a knob (12) which is rotatably connected to the knife shell (1) is arranged below the rotary spring (11), and the knob (12) is designed in a disc shape; one end of the rotary spring (11) is fixedly connected to the middle part of the knob (12), the right side of the knob (12) penetrates through the knife shell (1), and the side surface of the knob (12) is designed to be rough; the manual rotary knob (12) drives the rotary spring (11) to rotate, the rotary spring (11) rotates to drive the blade (2) to move up and down through the convex teeth (15), and the blade (2) extends out of the cutter shell (1) or retracts into the cutter shell (1);

two sides of the blade (2) are respectively provided with a first fixing plate (21) which is connected with the upper inner wall of the knife shell (1) in a sliding way; one surface, close to the blade (2), of the first fixing plate (21) is fixedly provided with a first knife sharpening plate (22), one surface, close to the blade (2), of the first knife sharpening plate (22) is provided with a second fixing plate (211), one surface, close to the blade (2), of the second fixing plate (211) is provided with a second knife sharpening plate (221), and the second knife sharpening plate (221) is attached to the blade (2); a gap is reserved between the first fixing plate (21) and the inner wall of the cutter shell (1), first air bags (23) are uniformly arranged in the gap, the first air bags (23) are fixedly connected between the inner wall of the cutter shell (1) and the first fixing plate (21), the first air bags (23) are in a compressed state, and third springs (29) are arranged between every two adjacent first air bags; the third spring (29) is fixedly connected between the inner wall of the cutter shell (1) and the first fixing plate (21); the first air bag (23) and the third spring (29) always push the first fixing plate (21) towards the blade (2), so that the second sharpening plate (221) is always attached to the blade (2), and the second fixing plate (211) can be pulled away.

2. The utility knife of claim 1, wherein: the first knife sharpening plate (22) is made of eighty-mesh abrasive; the first knife sharpening plate (22) and the second knife sharpening plate (221) are correspondingly provided with uniformly distributed open holes (24); the first fixing plate (21) and the second fixing plate (211) are both in a net-shaped design; the bottom of the blade (2) is fixedly connected with a second air bag (25), and the bottom of the blade shell (1) is provided with a through hole (26) for communicating the blade groove (13) with the outside.

3. The utility knife of claim 1, wherein: knife holes (27) are uniformly formed in the surface of the blade (2), so that the toughness of the blade (2) is improved.

4. The utility knife of claim 1, wherein: the convex teeth (15) arranged on the back of the blade (2) are designed in a saw blade shape.

5. The utility knife of claim 1, wherein: a cutting device (3) is arranged at the top of the knife shell (1); the cutting device (3) comprises a first sliding block (31), a second sliding block (32), a first fixing block (33), a second fixing block (34), a first spring (35) and a second spring (36), the first sliding block (31) and the second sliding block (32) are connected to the top of the cutter shell (1) in a sliding mode, and the first sliding block (31) and the second sliding block (32) are distributed at two ends of the cutter blade (2); a first fixing block (33) and a second fixing block (34) are respectively arranged between the first sliding block (31) and the blade (2) and between the second sliding block (32) and the blade; the first fixing block (33) and the second fixing block (34) are fixedly connected to the upper surface of the cutter shell (1); the side surfaces of one sides of the first sliding block (31) and the second sliding block (32) close to the blade (2) are respectively and fixedly connected with a first extrusion rod (37) and a second extrusion rod (38); the first extrusion rod (37) and the second extrusion rod (38) are both horizontally arranged, and the first extrusion rod (37) is higher than the second extrusion rod (38); a first spring (35) is sleeved on the surface of the first extrusion rod (37); the first spring (35) is fixedly connected between the first sliding block (31) and the first fixed block (33); a second spring (36) is sleeved on the surface of the second extrusion rod (38); the second spring (36) is fixedly connected between the second sliding block (32) and the second fixing block (34), and the first extrusion rod (37) and the second extrusion rod (38) penetrate through the first fixing block (33) and the second fixing block (34) and are not in contact with the blade (2); uniformly arranged nicks (28) are carved on the surface of the blade (2); the blade (2) is notched, and the blade (2) can be broken from the notch (28) by manually pressing the first slide block (31) and the second slide block (32) at the same time.

6. The utility knife of claim 5, wherein: a third air bag (4) fixedly connected to the top of the knife shell (1) is arranged between the first sliding block (31) and the first fixing block (33), a horizontally arranged sliding groove (41) is formed in the knife shell (1) below the third air bag (4), a third sliding block (42) is arranged in the sliding groove (41), the sliding groove (41) is communicated with the third air bag (4), and the third sliding block (42) is arranged in a manner of contacting with the blade (2); when the damaged blade (2) is broken, the third air bag (4) is squeezed to push the third sliding block (42) to fix the blade (2).