Flexible material cutting device, tire forming machine and cutting method

Abstract

The invention belongs to the technical field of tire forming, and particularly relates to a flexible material cutting device, a tire forming machine and a cutting method.A reciprocating motion mechanism drives a cutter to reciprocate in the width direction of a flexible material, and meanwhile a feeding mechanism drives the reciprocating motion mechanism to feed in the direction perpendicular to the flexible material; therefore, when the cutter feeds and cuts the flexible material in the thickness direction every time, the flexible material is cut off at a time in the width direction. The cutting efficiency is high, the cutter vibrates in the length direction of the cutter, and cutting is conducted in the whole length range at the same time, so that cutting of wide rubber materials can be completed within a short time, the heating value is small, original characteristics of various tire materials can be kept, and cost and energy consumption are low.

Description

Technical Field

[0001] The present invention belongs to the technical field of tire molding, and particularly relates to a flexible material cutting device, a tire molding machine and a cutting method. Background Art

[0002] In the production process of tires, the automation level and production efficiency of tire molding machines are getting higher and higher. At present, the vast majority of molding machines in China almost cut various rubber materials in advance in the feeding system and then automatically attach them to the molding drum of the main machine. This saves a lot of time compared to manual cutting after attachment on the drum.

[0003] For materials such as inner liners, sidewalls, treads, and cushion rubbers, ultrasonic cutting is mainly used at present. The advantages are that the heat generated during cutting is small, the temperature rise of the rubber compound is small, and a large cross-sectional groove can be generated, which is beneficial for head-to-tail bonding on the drum. The disadvantages are high cost, about more than 20,000 yuan per set. Another disadvantage is low cutting efficiency. The cutting knife needs to slowly cross the width of the material, and the vibration direction is perpendicular to the rubber strip, so as to break the rubber molecular chain. After cutting, the cutting knife needs to retract before starting the next cutting cycle.

[0004] There are also tire molding machines equipped with hot knife cutting devices, that is, using blades heated to about 180 degrees to cut the above-mentioned rubber compounds. This kind of cutting knife uses a temperature control system to control the temperature of the blade. Although the overall cost is not high, the problem is that if the temperature control is not precise enough, once the temperature is too high, it will cause pre-vulcanization of the rubber compound and damage the joint bonding quality. This kind of hot knife device also needs to cross the entire width when cutting wide-width materials, and the blade assembly needs to return to the original position after cutting to make the cutting enter the next working cycle, and the efficiency cannot be improved. Summary of the Invention

[0005] The purpose of the present invention is to solve the problems existing in the above-mentioned prior art and provide a flexible material cutting device.

[0006] The present invention is realized through the following technical solutions:

[0007] A flexible material cutting device includes a cutting knife, a reciprocating motion mechanism and a feeding mechanism; the reciprocating motion mechanism drives the cutting knife to perform reciprocating motion along the length direction of the cutting knife; the feeding mechanism drives the reciprocating motion mechanism to perform feeding motion along the width direction of the cutting knife.

[0008] Further, the reciprocating motion mechanism includes a vibrator, a parallelogram linkage mechanism, and a spring system; the parallelogram linkage mechanism includes a vibrating seat and a base arranged in parallel relative to each other. Both ends of the vibrating seat and the base are hinged by connecting rods, and one end of the vibrating seat is driven by the vibrator; the spring system includes a spring bracket and two springs. The upper end of the spring bracket is fixed on the base. The two springs are collinear and parallel to the length direction of the cutting knife and are arranged on the vibrating seat; one end of each spring is fixedly connected to the vibrating seat, and the other end is connected to the lower end of the spring bracket.

[0009] Further, the cutting knife is connected to the lower end of the vibrating seat, and the feeding mechanism is connected to the upper end of the base.

[0010] Further, the vibrator is a pneumatic vibrator or an electromagnetic vibrator.

[0011] Further, the spring bracket is a T-shaped bracket.

[0012] Further, both ends of the cutting knife are mounted on the vibrating seat through knife clips, and a tensioner is connected to one of the knife clips, and the tensioner is fixed on the vibrating seat.

[0013] The present invention also provides a tire forming machine, including the flexible material cutting device of the present invention.

[0014] The present invention also provides a method for cutting flexible materials, using the flexible material cutting device of the present invention, and including the following steps: the reciprocating motion mechanism drives the cutting knife to reciprocate along the width direction of the flexible material, and at the same time, the feeding mechanism drives the reciprocating motion mechanism to feed in the direction perpendicular to the flexible material, so that each time the cutting knife feeds into the flexible material along the thickness direction, the flexible material is cut off at one time in the width direction.

[0015] Further, the feeding process includes an idle running stage and a cutting stage. Before the cutting knife drops to a set distance h from the flexible material, it feeds quickly at a speed of v1 to drop the knife. After the cutting knife drops to a set distance h from the flexible material, it feeds slowly at a speed of v2 to cut into the flexible material, h>0, v1>v2.

[0016] Further, the natural vibration frequency is changed by adjusting the elastic coefficient of the spring system, and / or the frequency and amplitude of the reciprocating motion are adjusted by adjusting the vibration frequency of the vibrator.

[0017] Compared with the prior art, the beneficial effects of the present invention include:

[0018] 1. High cutting efficiency. The cutting knife vibrates in its length direction and cuts simultaneously within the entire length range. Therefore, it can complete the cutting of wide-width rubber materials in a short time.

[0019] 2. In the prior art, a heated cutting knife is generally used for cutting, which easily causes the rubber material to be heated and vulcanize prematurely. The present invention uses mechanical vibration drive for cutting, with small heat generation, belonging to cold cutting, which can ensure that the performance of tire materials does not change. The vibration amplitude of the cutting edge is generally very small, so the heat generation is very small, which is beneficial to various tire materials to maintain their original characteristics.

[0020] 3. In the prior art, an ultrasonic cutting knife is used, which is expensive. The present invention greatly reduces the cost while ensuring the same cutting quality.

[0021] 4. Since the present invention cuts the entire width simultaneously, the cutting time is very short, so the energy consumption is very low. Description of the Drawings

[0022] Figure 1 It is a schematic structural diagram of a cutting device;

[0023] Figure 2 It is Figure 1 a cross-sectional view of

[0024] Description of the reference numerals in the drawings: 1 - vibration seat, 2 - base, 3 - spring system, 4 - tool holder, 5 - tensioner, 6 - connecting rod, 7 - shaft, 8 - cutting knife, 9 - vibrator. Detailed Embodiment

[0025] The present invention will be further described in detail below with reference to the drawings:

[0026] A flexible material cutting device includes a cutting knife, a reciprocating motion mechanism and a feeding mechanism; the reciprocating motion mechanism drives the cutting knife to perform reciprocating motion along the length direction of the cutting knife; the feeding mechanism drives the reciprocating motion mechanism to perform feeding motion along the width direction of the cutting knife.

[0027] Preferably, as shown in Figure 1 in connection with Figure 2 , the reciprocating motion mechanism includes a vibrator 9, a parallelogram connecting rod mechanism and a spring system 3; the parallelogram connecting rod mechanism includes a vibration seat 1 and a base 2 which are arranged relatively parallel, both ends of the vibration seat 1 and the base 2 are hinged by a connecting rod 6, and one end of the vibration seat 1 is driven by the vibrator 9; the spring system 3 includes a spring bracket and two springs, the upper end of the spring bracket is fixed on the base 2, the two springs are collinear and parallel to the length direction of the cutting knife 8 and are arranged on the vibration seat 1; one end of each spring is fixedly connected to the vibration seat 1, and the other end is connected to the lower end of the spring bracket.

[0028] The vibration seat 1 can perform simple harmonic vibration relative to the base 2 under the action of the spring system 3, and form a linear reciprocating motion through the simple harmonic vibration.

[0029] Although the reciprocating motion can also be achieved by using a linear motor to drive the vibration seat 1, when a linear motor product is used as the driving source, it is not as convenient to install as a pneumatic vibrator or an electromagnetic vibrator. Moreover, the required vibration amplitude of this mechanism is very small and the frequency is relatively high, which is not very suitable for the linear motor although it can be used.

[0030] In this specific embodiment, the vibration seat 1 is one side of a parallelogram, and the base 2 is the other opposite side, so the two can move relative to each other. In actual implementation, other methods can also be adopted for the two, such as using a linear guide rail slider mechanism, which can also achieve the same effect.

[0031] The parallelogram link mechanism will cause the cutting knife to lift and fall. It will lift and fall once every vibration, but the amplitude of this lifting and falling is very small. Through calculation, when the amplitude is 170 Hz, the amplitude of the knife is about 0.11 mm, and the amplitude of the lifting and falling at this time is 0.00004 mm, which is very small, so it can be ignored.

[0032] The cutting knife 8 is installed on the vibration seat 1 through the knife clamp 4. The cutting knife 8 is in a long strip shape, and one of its long sides is sharpened and can be used for cutting.

[0033] Both ends of the cutting knife 8 are fixed by the knife clamp 4, and one of the knife clamps 4 at one end is connected to the tensioner 5. By adjusting the tensioner 5, the cutting knife 8 can be tensioned to make the cutting edge in a straight line state.

[0034] One end of the vibration seat 1 is equipped with a vibrator 9, and the vibrator 9 can adopt a market-ripe product in the form of pneumatic or electromagnetic, etc.

[0035] A spring system 3 is installed between the base 2 and the vibration seat 1, and it can adopt forms such as cylindrical helical compression springs, cylindrical helical tension springs, and disc springs. When the vibrator 9 is not working, its elastic coefficient K is the key parameter of this simple harmonic vibration system and determines the natural vibration frequency of the system.

[0036] The operation is as follows:

[0037] Turn on the vibrator 9 to generate an impact force on the vibration seat 1 at a certain frequency. The vibration seat 1 and the whole formed by the knife clamp 4, the tensioner 5, the cutting knife 8 and the vibrator 9 connected to it vibrate together, and the vibration direction is along the length direction of the cutting knife 8.

[0038] From Figure 1As can be seen, when vibrating, the two left and right connecting rods 6 will swing slightly. The spring system 3 consists of two springs and also includes a spring bracket fixed to the base 2. There is a screw in the middle of the bracket, and both springs are hung on this screw. When the impact force of the vibrator 9 pushes the vibrating seat 1 to the right, it generates a displacement to the right, so that the elongation length of the right spring increases and the elongation length of the left spring shortens. After the impact force of the vibrator 9 disappears, the vibrating seat 1 moves to the right to overcome the spring force and reaches the end point. Then the vibrator 9 generates a leftward impact force again. Under the combined action of the resultant force of the two spring forces and the impact force, the vibrating seat 1 moves from the right end point to the left. After moving to the middle balance point, under the action of inertia, it continues to move to the left. At this time, the direction of the resultant force of the spring force is opposite to the moving direction. When its kinetic energy is exhausted, it reaches the left end point. At this time, the vibrator 9 generates a rightward impact force again. Under the combined action with the resultant force of the spring force, the vibrating seat 1 moves to the right and starts a new cycle. It is not until the vibrator 9 is turned off that the device will return to a static state under the action of the shaft friction and air resistance.

[0039] After this device is installed on the tire building machine, the vibration of the cutter 8 along the length direction will form a sawing action on the rubber compound. During sawing, in cooperation with the cutter feeding action generated by the relevant mechanism on the feeding rack of the building machine, the cutting edge will penetrate into the rubber material until it is completely cut off.

[0040] The externally connected feeding mechanism (not shown in the figure, and the feeding mechanism can adopt the existing technology) is connected to the base 2 of this mechanism. From Figure 1 the perspective, the feeding direction is from top to bottom, and it is required that the feeding speed is uniform and stable. The feeding stroke can be divided into two sections. The first section is the idle running stage. (When the cutter is lifted, in order to prevent scraping with the tire material, generally a distance of about 40 mm needs to be reserved.) During the idle running stage, the cutter has not yet contacted the tire material, and at this time, it can fall at a relatively high speed. The second section is the cutting stage. When the cutting edge is about to contact the rubber compound, the feeding speed is switched to a low speed to allow the cutter to smoothly cut into the material. The feeding stroke in the second stage is approximately equal to the thickness of the material.

[0041] Advantages and effects: Through the implementation of the present invention, it can well optimize the existing tire building machine cutting mechanism in our country, improve the cutting effect, greatly reduce the equipment cost, and improve the cutting efficiency, thereby improving the working efficiency of the building machine.

[0042] Specifically, the vibrating rubber compound cutting device has the following advantages:

[0043] a. It has high cutting efficiency. The cutting knife vibrates in its length direction and performs cutting simultaneously within the entire length range. Therefore, it can complete the cutting of wide rubber materials in a short time. Currently, the ultrasonic knives, electric heating knives, or disc knives commonly installed in molding machines all cut gradually along the width direction of the material. The wider the material, the longer the time consumed. This device is suitable for cutting pure film materials without skeleton materials, such as inner liners, sidewalls, cushion rubbers, and treads. It can cut the left and right sidewalls or cushion rubbers located on the conveyor belt simultaneously.

[0044] b. The performance of the rubber material at the cut is not affected. In the industry, heated cutting knives are commonly used for cutting, which easily causes early vulcanization of the rubber material due to heat. This device uses mechanical vibration drive for cutting, generates little heat, belongs to cold cutting, and can ensure that the performance of tire materials does not change. For equipment operators and maintenance personnel, it can avoid burns and has good safety.

[0045] c. In the industry, ultrasonic cutting knives are widely used simultaneously, with high prices. The prices of spare parts are also very high. This device significantly reduces costs while ensuring the same cutting quality. As a spare part, there are many manufacturers and various product types of vibrators in the current market, with a wide range of choices, low prices, and fast supply.

[0046] d. Compared with the electric heating cutting device, this device can save approximately 50% of energy. During the operation of the electric heating cutting device, the heater keeps working to maintain the temperature of the cutting knife for cutting at any time. This device only consumes energy during the cutting process. Since the entire width is cut simultaneously and the cutting time is very short, the energy consumption is very low.

[0047] The specific working process of the above-mentioned patented vibrating rubber material cutting device is as follows:

[0048] When the vibrator 9 is not turned on, the entire device is a simple harmonic vibration device. The base 2 is relatively stationary, and the connecting rod 6 and the shaft 7 are respectively installed at both ends. The vibrating seat 1 is connected to the connecting rod 6, thus forming a parallelogram mechanism. The spring system 3 is installed between the base 2 and the vibrating seat 1. It can be seen that when the vibrating seat 1 and all the components installed on it (including two knife clamps 4, a tensioner 5, a cutting knife 8, and a vibrator 9) move left and right, they have to overcome the spring force. The elastic coefficient k of the left and right springs and the mass m of all the vibrating objects determine the vibration frequency and period of the system. When the vibrator 9 is turned on, the vibrator 9 applies excitation at its own frequency, thus forming a forced vibration, and the frequency of the entire device will be consistent with the frequency of the vibrator 9. When the vibrator 9 is turned off, the vibration of the device will quickly stop under the conditions of the rotating shaft and air resistance. Figure 1 It can be seen that when the vibrating seat 1 and all the components installed on it (including two knife clamps 4, a tensioner 5, a cutting knife 8, and a vibrator 9) move left and right, they have to overcome the spring force. The elastic coefficient k of the left and right springs and the mass m of all the vibrating objects determine the vibration frequency and period of the system. When the vibrator 9 is turned on, the vibrator 9 applies excitation at its own frequency, thus forming a forced vibration, and the frequency of the entire device will be consistent with the frequency of the vibrator 9. When the vibrator 9 is turned off, the vibration of the device will quickly stop under the conditions of the rotating shaft and air resistance.

[0049] When the cutting knife 8 vibrates together with components such as the vibration base 1, its vibration direction is along the length direction of the cutting knife. When it contacts the rubber material (such as the inner liner, sidewall, tread, cushion gum), the blade will cut the rubber material. The vibration amplitude of the blade is generally very small, so the heat generation is very small, which is beneficial to various tire materials to maintain their original characteristics.

[0050] When the vibrator 9 is a pneumatic vibrator, the air supply pressure can be adjusted to change the magnitude of the vibration force and the vibration frequency output. When the vibrator 9 is an electromagnetic-driven vibrator, its voltage can be adjusted to achieve the same adjustment purpose. Through the above adjustment methods, the vibration frequency and amplitude of this device can be conveniently set.

[0051] After the mechanism is adjusted, there is no need to adjust the frequency and amplitude anymore. However, for different specifications and different lengths of cutting knives, since the length of the tool holder is also different, the mass participating in the vibration is different. In order to achieve the same cutting effect, during the initial debugging, the frequency and amplitude of the entire mechanism need to be adjusted.

[0052] In this specific embodiment, the amplitude of the entire mechanism is adjusted to be between 0.1 and 0.8 millimeters, and the frequency is between 80 and 200 hertz, adopting a reciprocating vibration form.

[0053] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0054] In the description of the present invention, unless otherwise specified, the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0055] The above technical solutions are only specific embodiments of the present invention. For those skilled in the art, based on the disclosed principles of the present invention, it is very easy to make various types of improvements or deformations, not limited to the technical solutions described in the above specific embodiments of the present invention. Therefore, the foregoing description is only preferred and does not have a restrictive meaning.

Claims

1. A flexible material cutting device, characterized in that: it includes a cutting knife, a reciprocating motion mechanism and a feeding mechanism; the reciprocating motion mechanism drives the cutting knife to perform reciprocating motion along the length direction of the cutting knife; the feeding mechanism drives the reciprocating motion mechanism to perform feeding motion along the width direction of the cutting knife.

2. The flexible material cutting device according to claim 1, characterized in that: the reciprocating motion mechanism includes a vibrator, a parallelogram link mechanism and a spring system; the parallelogram link mechanism includes a vibrating seat and a base which are relatively parallelly arranged, both ends of the vibrating seat and the base are hinged by connecting rods, and one end of the vibrating seat is driven by the vibrator; the spring system includes a spring bracket and two springs, the upper end of the spring bracket is fixed on the base, the two springs are collinear and parallel to the length direction of the cutting knife and are arranged on the vibrating seat; one end of each spring is fixedly connected to the vibrating seat, and the other end is connected to the lower end of the spring bracket.

3. The flexible material cutting device according to claim 2, characterized in that: the cutting knife is connected to the lower end of the vibrating seat, and the feeding mechanism is connected to the upper end of the base.

4. The flexible material cutting device according to claim 2, characterized in that: the vibrator is a pneumatic vibrator or an electromagnetic vibrator.

5. The flexible material cutting device according to claim 2, characterized in that: the spring bracket is a T-shaped bracket.

6. The flexible material cutting device according to claim 1, characterized in that: both ends of the cutting knife are installed on the vibrating seat through knife clips, and a tensioner is connected to one of the knife clips, and the tensioner is fixed on the vibrating seat.

7. A tire building machine, characterized in that: it includes the flexible material cutting device according to any one of claims 1 to 6.

8. A flexible material cutting method, characterized in that: using the flexible material cutting device according to any one of claims 2 to 6, and including the following steps: the reciprocating motion mechanism drives the cutting knife to reciprocate along the width direction of the flexible material, and at the same time the feeding mechanism drives the reciprocating motion mechanism to feed in the direction perpendicular to the flexible material, so that each time the cutting knife feeds and cuts into the flexible material along the thickness direction, the flexible material is cut off at one time in the width direction.

9. The flexible material cutting method according to claim 8, characterized in that: the feeding process includes an idle running stage and a cutting stage. Before the cutting knife drops to a set distance h from the flexible material, it feeds and drops the knife quickly at a speed of v1. After the cutting knife drops to a set distance h from the flexible material, it feeds and cuts into the flexible material slowly at a speed of v2, h>0, v1>v2.

10. The flexible material cutting method according to claim 8, characterized in that: changing the natural vibration frequency by adjusting the elastic coefficient of the spring system, and / or adjusting the frequency and amplitude of the reciprocating motion by adjusting the vibration frequency of the vibrator.

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