阅读说明：本技术 一种球拍柄及其rtm成型模具、成型方法 (Racket handle and RTM (resin transfer molding) forming mold and method thereof ) 是由 井文奇 杜逸飞 张涛 田智立 魏洪峰 李卓达 刘雷波 夏雅男 于 2020-05-14 设计创作，主要内容包括：本发明涉及树脂基复合材料液态成型技术领域,尤其涉及一种球拍柄及其RTM成型模具、成型方法。球拍柄包括柄体,该柄体的一端具有用于容纳球框部或球杆部的腔体,在柄体内环绕腔体设置有减震层,拍击球后球杆部向球拍柄传递的震动会经过减震层阻断,能够有效阻断震动的传递,具有较好的减震性能,该减震层位于柄体的内部,不会影响柄体表面的刚度,更利于球员对拍柄进行操控和发力。另外,柄体由碳纤维树脂基复合材料制成,重量轻、结构强度高。RTM成型模具结构简单,能够批量生产内部具有减震层的球拍柄。RTM成型方法利用RTM成型模具,可以不用预浸料、热压罐,有效地降低设备成本、成型成本,且产品成型精度较高。(The invention relates to the technical field of resin-based composite material liquid forming, in particular to a racket handle, an RTM forming die and a forming method thereof. The racket handle includes the handle body, and the one end of this handle body has the cavity that is used for holding frame portion or club portion, is provided with the buffer layer around the cavity in the handle body, and the vibrations of racket portion to racket handle transmission can block through the buffer layer after the bat is strikeed, can effectively block the transmission of vibrations, has better shock attenuation performance, and this buffer layer is located the inside of the handle body, can not influence the rigidity on handle body surface, more does benefit to the sportsman and controls and give an emergency to the racket handle. In addition, the handle body is made of carbon fiber resin matrix composite material, and is light in weight and high in structural strength. The RTM forming die is simple in structure and can be used for batch production of racket handles with shock-absorbing layers inside. The RTM forming method utilizes the RTM forming die, prepreg and an autoclave are not needed, the equipment cost and the forming cost are effectively reduced, and the product forming precision is higher.)

1. A racket shaft, comprising:

the handle comprises a handle body, wherein one end of the handle body is provided with a cavity for mounting a ball frame part or a ball rod part, the cavity extends from the end part of the handle body along the axial direction of the handle body, and a damping layer arranged around the cavity is arranged inside the handle body;

the handle body is made of carbon fiber resin matrix composite.

2. A racket shaft according to claim 1, characterized in that: the weight body is used for adjusting the gravity center of the racket;

one end of the counterweight body is provided with a threaded connecting part;

the handle body is used for installing the end part of the counterweight body is provided with a threaded hole, and the counterweight body is connected with the handle body through the matching of the threaded connecting part and the threaded hole.

3. A racket shaft according to claim 1, characterized in that: the shock absorption layer is PMI foam.

4. A racket shaft according to claim 1, characterized in that: the carbon fibers in the carbon fiber resin matrix composite material are continuous long fibers.

5. A racket shaft according to claim 2, characterized in that: the counterweight body is made of carbon fiber resin matrix composite.

6. An RTM-forming mould for forming a racket shaft, as claimed in claim 1, comprising:

the lower die is provided with a first lower die cavity matched with the lower half part of the handle body on the die assembly surface, a fixed block lower containing cavity is arranged at one end corresponding to the first lower die cavity, a fixed block is detachably mounted in the fixed block lower containing cavity, a cavity core is fixed on the fixed block and matched with the cavity, one end of the cavity core is connected with the fixed block, the other end of the cavity core extends into the first lower die cavity, and the axis of the cavity core and the die assembly surface are positioned on the same plane;

the first lower cavity is communicated with at least one glue outlet;

the position, corresponding to the first lower cavity, of the joint surface of the upper die is provided with a first upper cavity matched with the upper half part of the handle body, and one end, corresponding to the first upper cavity, of the upper die is provided with an upper fixing block accommodating cavity corresponding to the lower fixing block accommodating cavity;

the first upper cavity is communicated with at least one glue injection port;

when the lower die and the upper die are closed, the first lower cavity and the first upper cavity form a handle body cavity matched with the handle body, and the cavity core is positioned in the handle body cavity.

7. An RTM-forming mould for forming a racket shaft, as claimed in claim 5, comprising:

the lower die is provided with a first lower cavity matched with the lower half part of the handle body on the die assembly surface of the lower die, two ends of the first lower cavity are respectively provided with a fixed block lower containing cavity, a fixed block is detachably mounted in each fixed block lower containing cavity, a cavity core is fixed on the corresponding fixed block and matched with the cavity, one end of the cavity core is connected with the corresponding fixed block, the other end of the cavity core extends into the first lower cavity, and the axis of the cavity core and the die assembly surface of the lower die are positioned on the same plane; a threaded hole mold core is fixed on the other fixing block, the threaded hole mold core is matched with the threaded hole, one end of the threaded hole mold core is fixed on the fixing block, the other end of the threaded hole mold core extends into the first lower cavity, and the threaded hole mold core and the cavity mold core are coaxially arranged;

a second lower cavity matched with the lower half part of the counterweight body is also arranged on the die joint surface of the lower die;

the first lower cavity and the second lower cavity are respectively communicated with at least one glue outlet;

the position, corresponding to the first lower cavity, of the joint surface of the upper die is provided with a first upper cavity matched with the upper half part of the handle body, and two ends of the first upper cavity are respectively provided with an upper fixing block accommodating cavity corresponding to the lower fixing block accommodating cavity;

a second upper cavity is further arranged at the position, corresponding to the second lower cavity, of the joint surface of the upper die, and the second upper cavity is matched with the upper half part of the counterweight body;

the first upper cavity and the second upper cavity are respectively communicated with at least one glue injection port;

when the lower die and the upper die are closed, the first lower cavity and the first upper cavity form a handle body cavity matched with the handle body, and the cavity core and the threaded hole core are respectively positioned at two ends in the handle body cavity; and the second lower cavity and the second upper cavity form a counterweight body cavity matched with the counterweight body.

8. An RTM forming method of a racket handle is characterized in that: use of a RTM forming mold according to claim 6, comprising the steps of:

determining the number of layers of the required two-dimensional fiber preforming body to be n layers according to the size of the racket handle, wherein n is a positive integer;

coating a release agent in the first lower cavity, the first upper cavity and the surface of the cavity core;

sequentially paving n/2 layers of the two-dimensional fiber preformed body in a first lower cavity, coating a layer of setting agent on each paved layer of the two-dimensional preformed body, paving at least one lower half part damping layer in the paving process, and installing the cavity core on the lower die through a fixing block to enable the cavity core to be positioned on the upper side of the paved two-dimensional fiber preformed body;

sequentially paving the remaining n/2 layers of the two-dimensional fiber preformed bodies on the upper side of the cavity core, coating a layer of setting agent on each paved layer of the two-dimensional preformed bodies, and paving at least one upper shock absorption layer in the paving process;

die assembly: and the die assembly interval between the upper die and the lower die is ensured to be zero;

injecting glue: slowly pressurizing to enable the resin to enter the handle body cavity through the glue injection port, and when the pressure is slowly increased to 0.6MPa, maintaining the pressure at 0.6MPa until no bubbles appear at the glue outlet, ending glue injection;

and (3) curing: placing the formed die after die assembly into an oven for curing;

demolding: separating the upper die from the lower die, separating the fixed block from the lower die, driving the formed handle body to be separated from the lower die through the cavity core, and separating the cavity core from the handle body along the axial direction of the handle body; and/or

The damping layer is PMI foam, before laying the PMI foam, is in PMI foam surface cladding glued membrane to evacuation in the glued membrane is guaranteed that the glued membrane closely adsorbs on PMI foam surface at room temperature.

9. An RTM forming method of a racket handle is characterized in that: use of a RTM forming mold according to claim 7, comprising the steps of:

determining the number of layers of the required two-dimensional fiber preforming body to be n layers according to the size of the racket handle, wherein n is a positive integer;

coating a release agent in the first lower cavity, the second lower cavity, the first upper cavity, the second upper cavity, the surface of the cavity core and the surface of the threaded hole core;

sequentially paving n/2 layers of the two-dimensional fiber preformed body in a first lower cavity, coating a layer of setting agent on each paved layer of the two-dimensional preformed body, paving at least one lower half part damping layer in the paving process, and respectively installing the cavity core and the threaded hole core in the lower containing cavities of the corresponding fixed blocks through the fixed blocks so that the cavity core and the threaded hole core are positioned at the upper sides of the paved two-dimensional fiber preformed body;

sequentially paving the remaining n/2 layers of the two-dimensional fiber preformed bodies on the upper sides of the cavity core and the threaded hole core, coating a layer of setting agent on each paved layer of the two-dimensional preformed bodies, and paving at least one upper half part damping layer in the paving process;

placing the three-dimensional fiber prefabricated body of the counterweight body into a second lower cavity;

die assembly: and the die assembly interval between the upper die and the lower die is ensured to be zero;

injecting glue: slowly pressurizing to enable the resin to enter the handle body cavity and the counterweight body cavity through the glue injection port, and when the pressure is slowly increased to 0.6MPa, maintaining the pressure at 0.6MPa until no bubbles appear at the glue outlet, finishing glue injection;

and (3) curing: placing the formed die after die assembly into an oven for curing;

demolding: separating the upper die from the lower die, separating the two fixing blocks from the lower die, driving the formed handle body to be separated from the lower die together through the cavity core and the threaded hole core, and separating the cavity core and the threaded hole core from the handle body along the axial direction of the handle body;

and separating the formed counterweight body from the mold.

10. The molding method according to claim 9, wherein: the damping layer is PMI foam, before laying the PMI foam, is in PMI foam surface cladding glued membrane to evacuation in the glued membrane is guaranteed that the glued membrane closely adsorbs on PMI foam surface at room temperature.

Technical Field

The invention relates to the technical field of resin-based composite material liquid forming, in particular to a racket handle, an RTM forming die and a forming method thereof.

Background

In the present market, a racket having a hitting frame portion and a holding handle portion, such as a badminton racket or a tennis racket, is provided, and the material of the handle portion is mainly wood or plastic. Wooden racket handle intensity is low, still can appear becoming flexible fracture and ageing under the sweat of user's soaking, and simultaneously, wooden racket handle's quality is also relatively heavier, does not conform to the big trend of losing weight for the racket at present. Plastic racquet shafts are relatively small and have a filler material inside, but are generally relatively unstable in structure and have poor shock absorption.

Disclosure of Invention

It is a first object of the present invention to provide a racket shaft having a light weight, a high structural strength and a good shock-absorbing property, so as to solve the aforementioned problems.

In order to achieve the first object, in a first aspect, the present invention provides a racket shaft, which in a first mode of realization comprises a shaft body, one end of which has a cavity for mounting a frame portion or a shaft portion, the cavity extending from the end of the shaft body in the axial direction of the shaft body, and the inside of the shaft body is provided with a damping layer arranged around the cavity;

the handle body is made of carbon fiber resin matrix composite.

With reference to the first implementation manner of the first aspect of the present invention, in a second implementation manner, the racket handle further includes a counterweight body for adjusting the center of gravity of the racket;

one end of the counterweight body is provided with a threaded connecting part;

the handle body is used for installing the tip of the counter weight body and has the screw hole, and the counter weight body passes through the cooperation of threaded connection portion and screw hole and is connected with the handle body.

With reference to the first or second implementation manner of the first aspect of the present invention, in a third implementation manner, the shock absorbing layer is a PMI foam.

With reference to any one of the first to third implementation manners of the first aspect of the present invention, in a fourth implementation manner, the carbon fibers in the carbon fiber resin-based composite material are continuous long fibers.

With reference to the second implementation manner of the first aspect of the present invention, in a fifth implementation manner, the counterweight body is made of a carbon fiber resin matrix composite material.

A second object of the invention is to provide an RTM-forming mould for forming a racket shaft.

In order to achieve the second object, in a second aspect, the present invention provides an RTM forming mold for forming a racket shaft in the first, third or fourth implementation of the first aspect of the present invention, wherein in the first implementation, the RTM forming mold comprises:

the lower die is provided with a first lower die cavity matched with the lower half part of the handle body on the die matching surface of the lower die, a fixed block lower containing cavity is arranged at one end corresponding to the first lower die cavity, a fixed block is detachably mounted in the fixed block lower containing cavity, a cavity core is fixed on the fixed block and matched with the cavity, one end of the cavity core is connected with the fixed block, the other end of the cavity core extends into the first lower die cavity, and the axis of the cavity core and the die matching surface are positioned on the same plane;

the first lower cavity is communicated with at least one glue outlet;

the position, corresponding to the first lower cavity, of the matched die surface of the upper die is provided with a first upper cavity matched with the upper half part of the handle body, and one end, corresponding to the first upper cavity, of the upper die is provided with an upper fixed block accommodating cavity corresponding to the lower fixed block accommodating cavity;

the first upper cavity is communicated with at least one glue injection port;

when the lower die and the upper die are closed, the first lower die cavity and the first upper die cavity form a handle body die cavity matched with the handle body, and the cavity die core is positioned in the die handle body cavity.

In a third aspect, the present invention provides an RTM forming apparatus for forming a racket shaft according to the fifth implementation form of the first aspect of the present invention, wherein in the first implementation form thereof, the RTM forming apparatus comprises:

the lower die is provided with a first lower die cavity matched with the lower half part of the handle body on the die assembly surface of the lower die, two ends of the first lower die cavity are respectively provided with a fixed block lower containing cavity, a fixed block is detachably mounted in each fixed block lower containing cavity, a cavity core is fixed on one corresponding fixed block, the cavity core is matched with the cavity, one end of the cavity core is connected with the corresponding fixed block, the other end of the cavity core extends into the first lower die cavity, and the axis of the cavity core and the die assembly surface of the lower die are positioned on the same plane; a threaded hole mold core is fixed on the other fixing block, the threaded hole mold core is matched with the threaded hole, one end of the threaded hole mold core is fixed on the fixing block, the other end of the threaded hole mold core extends into the first lower cavity, and the threaded hole mold core and the cavity mold core are coaxially arranged;

a second lower cavity matched with the lower half part of the counterweight body is also arranged on the die joint surface of the lower die;

the first lower cavity and the second lower cavity are respectively communicated with at least one glue outlet;

the upper die is provided with a first upper die cavity matched with the upper half part of the handle body at a position corresponding to the first lower die cavity on the die joint surface of the upper die, and two ends of the first upper die cavity are respectively provided with an upper fixed block accommodating cavity corresponding to the lower fixed block accommodating cavity;

a second upper cavity is arranged at the position, corresponding to the second lower cavity, of the matched surface of the upper die, and the second upper cavity is matched with the upper half part of the counterweight body;

the first upper cavity and the second upper cavity are respectively communicated with at least one glue injection port;

when the lower die and the upper die are closed, the first lower cavity and the first upper cavity form a handle body cavity matched with the handle body, and the cavity core and the threaded hole core are respectively positioned at two ends of the handle body cavity; the second lower cavity and the second upper cavity form a counterweight body cavity matched with the counterweight body.

A third object of the present invention is to provide a RTM method of forming a racket shaft.

In order to achieve the third object, according to a fourth aspect of the present invention, an RTM method for forming a racket shaft without a weight body, mainly using the RTM mold according to the first implementation manner of the second aspect, includes the following steps:

determining the number of layers of the required two-dimensional fiber preforming body to be n layers according to the size of the racket handle, wherein n is a positive integer;

coating a release agent in the first lower cavity, the first upper cavity and the surface of the cavity core;

sequentially laying n/2 layers of two-dimensional fiber preformed bodies in a first lower cavity, coating a layer of setting agent on each laid two-dimensional preformed body, laying at least one lower half part damping layer in the laying process, and mounting a cavity core on a lower die through a fixing block to enable the cavity core to be positioned on the upper side of the laid two-dimensional fiber preformed body;

sequentially paving the remaining n/2 layers of two-dimensional fiber preformed bodies on the upper side of the cavity core, coating a layer of setting agent on each paved two-dimensional preformed body, and paving at least one upper half shock-absorbing layer in the paving process;

die assembly: and the die assembly interval between the upper die and the lower die is ensured to be zero;

injecting glue: slowly pressurizing to enable the resin to enter the handle body cavity through the glue injection port, and when the pressure is slowly increased to 0.6MPa, maintaining the pressure at 0.6MPa until no bubbles appear at the glue outlet, ending glue injection;

and (3) curing: placing the formed die after die assembly into an oven for curing;

demolding: and separating the upper die from the lower die, separating the fixing block from the lower die, driving the formed handle body to be separated from the lower die through the cavity core, and separating the cavity core from the handle body along the axial direction of the handle body.

With reference to the first implementation manner of the fourth aspect, in a second implementation manner of the fourth aspect of the present invention, the damping layer is PMI foam, before the PMI foam is laid, an adhesive film is coated on the surface of the PMI foam, and vacuum is pumped in the adhesive film at room temperature, so as to ensure that the adhesive film is tightly adsorbed on the surface of the PMI foam.

In order to achieve the third object, according to a fifth aspect of the present invention, there is provided an RTM method for forming a racket shaft, which is mainly for forming a racket shaft having a weight body by using the RTM mold according to the first implementation manner of the third aspect, wherein in the first implementation manner, the method comprises the steps of:

determining the number of layers of the required two-dimensional fiber preforming body to be n layers according to the size of the racket handle, wherein n is a positive integer;

coating a release agent in the first lower cavity, the second lower cavity, the first upper cavity, the second upper cavity, the surface of the cavity core and the surface of the threaded hole core;

sequentially laying n/2 layers of two-dimensional fiber preformed bodies in a first lower cavity, coating a layer of setting agent on each laid two-dimensional preformed body, laying at least one lower half part damping layer in the laying process, and respectively installing a cavity core and a threaded hole core in corresponding lower containing cavities of the fixing blocks through one fixing block so that the cavity core and the threaded hole core are positioned at the upper side of the laid two-dimensional fiber preformed bodies;

sequentially paving the rest n/2 layers of two-dimensional fiber preformed bodies on the upper sides of the cavity core and the threaded hole core, coating a layer of setting agent on each paved layer of two-dimensional preformed body, and paving at least one upper half part damping layer in the paving process;

placing the three-dimensional fiber prefabricated body of the counterweight body into a second lower cavity;

die assembly: and the die assembly interval between the upper die and the lower die is ensured to be zero;

injecting glue: slowly pressurizing to enable the resin to enter the handle body cavity and the counterweight body cavity through the glue injection port, and when the pressure is slowly increased to 0.6MPa, maintaining the pressure at 0.6MPa until no bubbles appear at the glue outlet, finishing glue injection;

and (3) curing: placing the formed die after die assembly into an oven for curing;

demolding: separating the upper die from the lower die, separating the two fixing blocks from the lower die, driving the formed handle body to be separated from the lower die through the cavity core and the threaded hole core, and separating the cavity core and the threaded hole core from the handle body along the axial direction of the handle body;

and separating the formed counterweight body from the mold.

In combination with the first implementation manner of the fourth aspect, in the second implementation manner of the fourth aspect, the damping layer is PMI foam, before the PMI foam is laid, an adhesive film is coated on the surface of the PMI foam, and the interior of the adhesive film is vacuumized at room temperature, so that the adhesive film is ensured to be tightly adsorbed on the surface of the PMI foam.

The technical scheme of the invention has the following advantages: the racket handle comprises a handle body, wherein one end of the handle body is provided with a cavity for accommodating the racket frame part or the racket rod part, a damping layer is arranged in the handle body around the cavity, vibration transmitted to the racket handle by the racket rod part after a racket is struck can be blocked by the damping layer, the transmission of the vibration can be effectively blocked, the racket handle has better damping performance, and the damping layer is positioned in the handle body, so that the rigidity of the surface of the handle body cannot be influenced, and the racket handle can be controlled and applied with force by players. In addition, the handle body is made of carbon fiber resin matrix composite material, and is light in weight and high in structural strength.

The racket handle is also provided with a balance weight body, the other end of the handle body is provided with a threaded hole matched with the balance weight body, and the gravity center of the racket can be conveniently adjusted by adjusting the weight or the length.

The RTM forming die provided by the invention is simple in structure and can be used for producing racket handles with shock-absorbing layers in batches.

The RTM forming method of the racket handle provided by the invention utilizes the RTM forming die, does not need prepreg and an autoclave, effectively reduces the equipment cost and the forming cost, and has higher product forming precision.

Drawings

The drawings of the present invention are provided for illustrative purposes only, and the proportion and the number of the components in the drawings do not necessarily correspond to those of an actual product.

FIG. 1 is a schematic front view of a racket shaft according to an embodiment of the present invention;

FIG. 2 is a schematic sectional view taken along line A-A of FIG. 1;

fig. 3 is a schematic half-sectional view of a counterweight body according to an embodiment of the invention;

FIG. 4 is a schematic front view showing the structure of a racket shaft according to a second embodiment of the present invention;

FIG. 5 is a schematic sectional view taken along line B-B of FIG. 4;

FIG. 6 is an exploded view of a molding die according to a third embodiment of the present invention;

FIG. 7 is a schematic structural diagram of a lower mold according to a third embodiment of the present invention;

FIG. 8 is a schematic structural diagram of an upper mold according to a third embodiment of the present invention;

FIG. 9 is an exploded view of a molding die according to a fourth embodiment of the present invention

Fig. 10 is a schematic structural view of an upper die in the fourth embodiment of the present invention.

In the figure: 100: a racket shaft; 101: a handle body; 1011: a cavity; 1012: a shock-absorbing layer; 102: a counterweight body;

200: RTM forming mould; 201: a lower die; 2011: a first lower cavity; 2012: a lower accommodating cavity of the fixing block; 2013: a glue outlet; 2014: a second lower cavity; 202: an upper die; 2021: a first upper cavity; 2022: the fixed block is provided with an accommodating cavity; 2023: a glue injection port; 2024: a second upper cavity; 203: a fixed block; 204: a cavity mold core; 205: and (4) a threaded hole mold core.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

Interpretation of terms: RTM is the acronym RTM from English Resin Transfer Molding and refers to Resin Transfer Molding technology.