Bow arm

Abstract

The utility model discloses a bow arm, which belongs to the technical field of bows and arrows and comprises a bow arm body, the bow arm body is formed by thermally pressing bow arm materials, and the bow arm materials are formed by superposing a plurality of layers of glass fiber prepreg cloth. The service life of the bow manufactured by the bow arm is greatly prolonged, the bow can be launched for more than one hundred thousand times, the influence of environment temperature and humidity is avoided, and the bow can be wound and stored for a long time. The bow arm is formed by superposing and hot-pressing bow arm materials, compared with glass fiber reinforced plastic wet forming, complex operation steps are not needed, and machining of a needed metal mold becomes easy and simple.

Description

Technical Field

[0001] The utility model belongs to the technical field of bows and arrows and relates to a bow arm. Background Art

[0002] When the bowstring is pulled, the bow arm will bend, and this bending is called elastic deformation. This elastic deformation process is the process of energy storage of the bow. The greater the energy storage, the farther the arrow can be shot. Therefore, the material and process of the bow arm are crucial.

[0003] The ancient bow making method uses animal and plant materials, generally cattle tendons and wood. The production process is extremely complicated and is seriously affected by the ambient temperature and humidity during use. In the 1950s and 1960s, with the development and use of composite materials, the bows used by athletes in archery competitions were made by sandwiching wood sheets between two layers of fiberglass sheets. We call them laminated bows. This process has also been used by many domestic manufacturers to make bows. Laminated bows have many weaknesses because the bow arms use bamboo and wood as interlayers. First, the service life is short (20,000 to 50,000 shots), second, it cannot be made into a bow with a large poundage (less than 60 pounds), third, it is greatly affected by humidity and temperature, and fourth, the stability is poor (the bowstring must be removed after use, otherwise the poundage will drop).

[0004] Regarding fiber-reinforced composite materials, they are divided into glass fiber reinforced composite plastics, carbon fiber reinforced composite plastics, etc. according to the different fibers used. It is a composite material with glass fiber and carbon fiber as reinforcing materials and synthetic resin as matrix material. This composite material is widely used in military equipment, industrial products and civilian products. According to different physical properties and requirements, there are many kinds of production processes for composite materials. In terms of the form of fibers, there are unidirectional continuous fibers, chopped fibers and fiber cloths. Fiber cloths are plain cloth, twill cloth and unidirectional cloth mainly in one direction. In terms of resins, there are phenolic resins, polyester resins, epoxy resins, etc. In terms of the molding process of composite materials, there are hand lay-up process, pressing process, winding process, injection molding process, etc. In these processes, the fibers are generally impregnated with resin first, and then the next step is carried out. Another process is fiber prepreg. This prepreg is a fiber impregnated with resin and coated, and exists in the form of raw materials for composite materials. It can be stored and transported in a short period of time. This will make the production of some composite materials simple and fast. This kind of prepreg fiber generally exists in the form of sheet-like unidirectional continuous fiber, chopped fiber and cloth, which we usually call resin prepreg and resin prepreg cloth.

[0005] Therefore, how to apply the resin prepreg molding process in bow manufacturing to develop a bow arm is an urgent problem to be solved by technical personnel in this field. Utility Model Content

[0006] In view of this, the utility model provides a bow arm.

[0007] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0008] A limb includes a limb body, wherein the limb body is formed by hot pressing of limb material, wherein the limb material includes multiple layers of glass fiber prepreg cloth stacked together, and the glass fiber prepreg cloth is glass fiber cloth impregnated with resin.

[0009] Beneficial effects of the utility model: the bow made of the bow arm of the utility model greatly improves the service life of the bow, which can be launched more than 100,000 times, is not affected by ambient temperature and humidity, and the bow can be strung and stored for a long time regardless of whether it is used or not.

[0010] The bow arm of the utility model is formed by superimposing bow arm materials and hot pressing. Compared with the wet forming of glass fiber reinforced plastics (fiber impregnation and metal mold sealing film cavity), it does not require complicated operation steps and the processing of the required metal mold also becomes easy and simple.

[0011] Furthermore, the fabric structure of the glass fiber prepreg is unidirectional, and the fiber density is 200g / m 2 , the resin is epoxy resin.

[0012] Furthermore, the thickness of a single layer of the glass fiber prepreg is 0.2 mm, and the total number of layers of the glass fiber prepreg is 15-25 layers.

[0013] Furthermore, multiple layers of carbon fiber prepreg are stacked on both sides of the multiple layers of glass fiber prepreg, and the carbon fiber prepreg is a carbon fiber cloth impregnated with resin.

[0014] The beneficial effects of adopting the above further technical solution are as follows: superimposing carbon fiber prepreg can increase the elastic range of the bow arm and increase the rebound speed.

[0015] Furthermore, the fabric structure of the carbon fiber prepreg is unidirectional or twill, and the fiber density is 200g / m 2 , the resin is epoxy resin.

[0016] Furthermore, the thickness of a single layer of the carbon fiber prepreg is 0.2 mm, the total number of layers of the carbon fiber prepreg is 8-12 layers, and the total number of layers of the glass fiber prepreg is 7-13 layers.

[0017] Furthermore, 4 to 6 layers of carbon fiber prepreg are stacked on both sides of the above-mentioned multi-layer glass fiber prepreg.

[0018] Furthermore, the above-mentioned multi-layer glass fiber prepreg cloth is divided into three parts: upper, middle and lower. Among them, the glass fiber prepreg cloth in the middle part is located at the handle of the bow arm, and the length of each layer thereof changes in steps according to the length requirement of the handle, and the number of layers is set according to the thickness requirement of the handle.

[0019] Furthermore, the number of layers of the glass fiber prepreg cloth in the upper part is 7-12, the number of layers of the glass fiber prepreg cloth in the lower part is 8-13, and the number of layers of the glass fiber prepreg cloth in the middle part is 4-6. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall structure of the bow arm body;

[0021] Figure 2 It is a schematic diagram of the structure of the bow arm material formed by stacking multiple layers of glass fiber prepreg;

[0022] Figure 3 The schematic diagram of the structure of the bow arm material is that multiple layers of carbon fiber prepreg are stacked on both sides of multiple layers of glass fiber prepreg;

[0023] Figure 4 A schematic diagram of the structure of a bow arm material in which the lengths of the layers of glass fiber prepreg in the middle part of the handle of the bow arm are changed in a stepwise manner;

[0024] Among them, 1-bow arm body, 2-handle, 3-glass fiber prepreg cloth, 4-carbon fiber prepreg cloth. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] like Figure 1-2 As shown, the limb includes a limb body 1, which is formed by hot pressing of limb material. The limb material includes multiple layers of glass fiber prepreg cloth 3 stacked together, and the glass fiber prepreg cloth 3 is glass fiber cloth impregnated with resin.

[0027] In one embodiment, the fabric structure of the glass fiber prepreg 3 is unidirectional, and the fiber density is 200g / m 2 , the resin is epoxy resin.

[0028] In one embodiment, the thickness of a single layer of glass fiber prepreg cloth 3 is 0.2 mm, and the total number of layers of glass fiber prepreg cloth 3 is 15-25 layers.

[0029] like Figure 3 As shown, in one embodiment, multiple layers of carbon fiber prepreg cloth 4 are stacked on both sides of the multiple layers of glass fiber prepreg cloth 3, and the carbon fiber prepreg cloth 4 is a carbon fiber cloth impregnated with resin.

[0030] In one embodiment, the fabric structure of the carbon fiber prepreg 4 is unidirectional or twill, and the fiber density is 200g / m 2 , the resin is epoxy resin.

[0031] In one embodiment, the thickness of a single layer of carbon fiber prepreg 4 is 0.2 mm, the total number of layers of carbon fiber prepreg 4 is 8-12 layers, and the total number of layers of glass fiber prepreg 3 is 7-13 layers.

[0032] In one embodiment, 4 to 6 layers of carbon fiber prepreg 4 are stacked on both sides of the multiple layers of glass fiber prepreg 3 .

[0033] like Figure 4 As shown, in one embodiment, the multi-layer glass fiber prepreg cloth 3 is divided into three parts: upper, middle and lower. Among them, the glass fiber prepreg cloth 3 in the middle part is located at the handle 2 of the bow arm, and the length of each layer thereof changes in steps according to the length requirement of the handle 2, and the number of layers is set according to the thickness requirement of the handle 2.

[0034] In one embodiment, the number of layers of the glass fiber prepreg cloth 3 in the upper portion is 7-12, the number of layers of the glass fiber prepreg cloth 3 in the lower portion is 8-13, and the number of layers of the glass fiber prepreg cloth 3 in the middle portion is 4-6.

[0035] The method for preparing a bow arm comprises the following steps:

[0036] (1) cutting the glass fiber prepreg 3 and / or the carbon fiber prepreg 4 according to the width requirement of the limb;

[0037] (2) stacking multiple layers of glass fiber prepreg 3 and / or multiple layers of carbon fiber prepreg 4 according to the material of the bow arm;

[0038] (3) an open metal mold is designed according to the bow shape of the bow arm, and both ends of the metal mold are located at the two ends of the bow arm and are connected to the outside world;

[0039] (4) placing the limb material between the upper and lower dies of the metal mold, closing the mold, and heating and pressurizing the metal mold. The heating temperature is carried out according to the following heating curve: first, the temperature is raised from room temperature to 80° C. over 30 minutes, maintained at 80° C. for 30 minutes, and then the temperature is raised from 80° C. to 135° C. over 30 minutes, and maintained at 135° C. for 60 minutes; the continuous pressurization pressure is 8-10 MPa, the metal mold is cooled to room temperature, the mold is opened, the limb blank is taken out, and the excess part is cut off;

[0040] (5) Grinding the bow arm blank to obtain the bow arm.

[0041] Compared with the laminated bow, the product performance of this utility model is shown in Table 1:

[0042] Table 1

[0043]

[0044] The disclosed embodiments are described to enable those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A bow arm, characterized in that: The bow arm body is formed by hot pressing of the bow arm material, and the bow arm material is formed by stacking multiple layers of glass fiber prepreg cloth, and the glass fiber prepreg cloth is glass fiber cloth impregnated with resin, and the thickness of a single layer of the glass fiber prepreg cloth is 0.2 mm; The total number of layers of the glass fiber prepreg is 15-25 layers; or, multiple layers of carbon fiber prepreg are stacked on both sides of the multiple layers of glass fiber prepreg, the carbon fiber prepreg is a carbon fiber cloth impregnated with resin, the thickness of a single layer of the carbon fiber prepreg is 0.2 mm, the total number of layers of the carbon fiber prepreg is 8-12 layers, the total number of layers of the glass fiber prepreg is 7-13 layers, and 4-6 layers of carbon fiber prepreg are stacked on both sides of the multiple layers of glass fiber prepreg; The multi-layer glass fiber prepreg cloth is divided into three parts: upper, middle and lower. The glass fiber prepreg cloth in the middle part is located at the handle of the bow arm, and the length of each layer thereof changes in a step-by-step manner according to the length requirement of the handle. The number of layers of the glass fiber prepreg cloth in the upper part is 7-12, the number of layers of the glass fiber prepreg cloth in the lower part is 8-13, and the number of layers of the glass fiber prepreg cloth in the middle part is 4-6.

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