110 results about "Needle valve" patented technology

This invention provides an electric valve and a refrigeration cycle system. The electric valve has a two-stage flow control domain. The main valve port of the main valve seat is fully closed by the main valve core, and the refrigerant flow is controlled in the small flow control domain by the throttling section formed between the auxiliary valve port and the needle valve formed by the main valve core. For this electric valve, vibration of the main valve core in the small flow control domain is prevented, and the controllability in the small flow domain is improved. The main valve port (13a) is fully closed by the main valve core (3), and fluid flows through the throttling section (gap) between the needle part (42) of the needle valve (4) and the auxiliary valve port (33a), thus forming a small flow control domain. In the small flow control domain, the conical part (41a) (abutment part) of the needle valve (4) (auxiliary valve core) abuts against the stepped part (3a) (abutment part) of the main valve core (3). By abutting the tapered part (41a) and the stepped part (3a), the needle valve (4) pushes the main valve core (3) to the side of the main valve seat (13).

This utility model relates to the field of metering pump technology, and in particular to a single-head needle valve metering pump. It includes a metering pump body, which is equipped with an inlet / outlet needle valve switching mechanism for switching the inlet and outlet liquid flow channels. The switching mechanism includes a base connected to the metering pump body, and an inlet needle valve and an outlet needle valve respectively disposed on the base and mutually switching between each other. The base has a T-shaped flow channel communicating with the metering pump body, the inlet needle valve, and the outlet needle valve. When liquid enters the metering pump body, the inlet needle valve is in the open state, communicating with the T-shaped flow channel; when the outlet needle valve is blocked from the T-shaped flow channel, it is in the closed state. This utility model has a simpler structure. Through the mutual switching of the inlet and outlet needle valves, a smooth switching between liquid entry and exit of the metering pump body is achieved. Furthermore, the inlet / outlet needle valve switching mechanism can withstand high pressure, has sufficient thrust, and a fast flow rate, meeting the requirements of high-pressure metering pump use and improving the reliability and stability of the metering pump.

This invention relates to a needle valve venting nozzle, comprising a nozzle body and multiple valve needles mounted on the nozzle body. The nozzle body has a material conveying channel at its axial center, and multiple venting holes perpendicular to the axial direction are provided on the middle sidewall of the nozzle body. The valve needles are inserted into the venting holes, and the diameter of the venting holes is 2-15 μm larger than the diameter of the valve needles. This invention has a simple structure and, without affecting extrusion efficiency and melt stability, enables the nozzle itself to have good venting function, thereby actively expelling residual gas before the material enters the mold, ensuring sufficient drying of the material and stable product quality.

This invention discloses an online detection method and device for the interlayer vacuum degree of multi-layer insulation in cryogenic containers, belonging to the field of cryogenic insulation vacuum detection technology. The method includes: installing a vacuum-sealed base on the outer wall of the container; penetrating the outer liner with a piercing capillary probe and inserting it into the interlayer gap; constructing a two-stage high-vacuum differential system consisting of an oil-free dry forepump, a turbomolecular pump, a fine-tuning needle valve, a flow-limiting capillary, a differential chamber, and a residual gas analyzer to form a low-speed drainage loop; after pre-evacuating the background gas, adjusting the fine-tuning needle valve to extract the interlayer gas at low speed, simultaneously collecting the total pressure and component partial pressures; calculating the true vacuum degree by combining flow resistance, gas resistance, permeation resistance, and temperature correction; after detection, leaving the end of the piercing capillary probe inside the layer without removing it, and permanently sealing the base port; repeating the detection at different points and depths to complete a full-area scan. This application has the advantages of direct online detection, minimally invasive and leak-free operation, repeatable testing, and accurate tracing of failure causes.

This invention discloses a high-temperature chemical solution supply system for cleaning substrates. The system includes a solution tank for containing a chemical solution; a first pump, the inlet of which is connected to the solution tank, and the outlet of which is connected to a buffer tank; a buffer tank including a tank body, an exhaust pipe, and a needle valve, one end of which is connected to the tank body and the other end to the solution tank, and the needle valve mounted on the exhaust pipe for regulating the pressure within the buffer tank; and a second pump, the inlet of which is connected to the buffer tank, and the outlet of which is connected to a cleaning chamber for cleaning the substrate. When the second pump is in the open state, the first pump and the needle valve are also in the open state. The pressure within the buffer tank is regulated by the needle valve and the first pump, causing the chemical solution in the buffer tank to be forced into the inlet of the second pump. This invention also provides a substrate cleaning apparatus including a high-temperature chemical solution supply system and an ultrasonic / megasonite device, as well as a method for cleaning substrates.

The application discloses a kind of filling device and filling method for high-precision energy storage immersed liquid, it is related to energy storage equipment filling technical field, to solve the problem of insufficient precision of existing filling equipment, easy to introduce bubble and low degree of automation.The device includes sequentially connected oil storage tank, gear pump, defoaming chamber, steady flow tank and needle valve, needle valve is sealedly connected with the cooling system to be filled by quick-change connector;Defoaming chamber is built-in baffle and vacuum pump, for eliminating immersed liquid bubble;Steady flow tank is equipped with air bag and pressure regulating valve, absorbs gear pump pulsation to maintain constant pressure, overall realizes automatic operation by PLC controller.The filling method uses "first fast then slow" speed curve, combined with drop mode and pressure maintaining step to improve precision.The application filling precision is high, no bubble is mixed, degree of automation is high, can satisfy the strict requirement of high-precision energy storage equipment to immersed liquid filling, adapt to the scale production demand of energy storage cooling system.

This utility model relates to a common rail injector with replaceable control valves, including a solenoid valve assembly, a metering block assembly, a needle valve assembly, and a locking cap. The solenoid valve assembly includes an injector body, an electromagnet, an armature, a control valve core, a first spring, and a valve ball, with the valve ball detachably mounted on the lower end of the control valve core. The metering block assembly includes a metering block and a ball valve seat, with the ball valve seat detachably fixed in a mounting groove. The needle valve assembly includes a needle valve body, a needle valve core, a control chamber sleeve, and a second spring. The injector body, metering block, and needle valve body are arranged sequentially from top to bottom and detachably fixed together by the locking cap. This utility model is easy to maintain and adjust, and can better meet the usage requirements of marine electronically controlled common rail fuel systems.

This utility model discloses a dual-fuel injector and a dual-fuel engine for preventing end leakage, including a needle valve body. A fuel A needle valve is disposed inside the needle valve body, and a fuel B needle valve is disposed inside the fuel A needle valve. Multiple annular protrusions are disposed on the bottom surface of the fuel A needle valve near the needle valve body. These annular protrusions increase the heat-receiving area at the bottom of the fuel A needle valve, causing the bottom of the fuel A needle valve to expand upon heating, thus reducing the gap between the bottom of the fuel A needle valve and the needle valve body. This utility model, through the combination of the annular protrusions and the frustum-shaped pressure chamber protrusions, increases the amount of thermal expansion and reduces the gap. It can achieve a dynamic seal between the fuel A needle valve and the needle valve body, allowing the fuel A needle valve to automatically expand and fill the gap when the temperature rises, making it particularly suitable for high-frequency injectors.

This application relates to a fuel injector, engine, and mechanical device in the field of engine technology. The fuel injector includes an injector body, a needle valve body disposed at one end of the injector body, a needle valve disposed within the needle valve body, and a nozzle cap for connecting the needle valve body to the injector body. The nozzle cap is fitted onto the needle valve body, and an annular cavity is formed between the inner surface of the nozzle cap and the outer surface of the needle valve body. The annular cavity is located at the end of the nozzle cap away from the injector body. A suitable sealing gasket is placed within the annular cavity, and an interference gasket is fitted onto the needle valve body near the sealing gasket. The fuel injector of this application can reduce the possibility of combustion products entering the injector shoulder, improve the protection of the injector shoulder, and extend the service life of the injector.

The application relates to a methanol engine fuel atomization injection optimization structure, which comprises a nozzle body, a needle valve, a temperature-sensitive displacement driving assembly and a shielding sliding sleeve; a low-temperature cavitation-promoting micro-texture area and a high-temperature cavitation-suppressing micro-texture area are arranged on the outer surface of the needle valve in an axial direction; the temperature-sensitive displacement driving assembly is used for outputting axial displacement in response to the change of the ambient temperature of the head of the nozzle body and driving the shielding sliding sleeve to switch between a first limit position and a second limit position; when the shielding sliding sleeve is located at the first limit position, the high-temperature cavitation-suppressing micro-texture area is shielded and the low-temperature cavitation-promoting micro-texture area is exposed to methanol fluid; when the shielding sliding sleeve is located at the second limit position, the low-temperature cavitation-promoting micro-texture area is shielded and the high-temperature cavitation-suppressing micro-texture area is exposed to methanol fluid; the flow in the nozzle body forms a cavitation-enhanced atomization state in a low-temperature working condition and a stable-flowing cavitation-suppressing state in a high-temperature working condition. The application can automatically trigger regulation and control in response to temperature without additional sensors and actuators.

This utility model discloses a rotary printing press, comprising: a rotary cylinder assembly; and an oil dripping assembly, disposed on one side of the rotary cylinder assembly along a first direction, including a vertical plate, a connecting rod, multiple movable supports, and multiple needle valve-type oil cups. The vertical plate extends along a second direction and is spaced apart along a third direction. The connecting rod extends along a third direction, with both ends connected to the vertical plate and spaced apart along the second direction. The multiple movable supports are spaced apart along the third direction and correspond one-to-one with the multiple needle valve-type oil cups. One end of each movable support is slidably engaged with the connecting rod, and the other end is connected to the needle valve-type oil cup for dripping oil into the rotary cylinder assembly. The vertical plate and connecting rod form a three-dimensional frame, and the design of one-to-one correspondence between the needle valve-type oil cups and the movable supports allows for flexible adjustment of the oil cup position through the sliding supports. The needle valves can control the oil volume at a single point, and the sliding design of the supports can match the lubrication requirements of paper of different widths without the need for component replacement.

Provided is an electric valve and a refrigeration cycle system. In an electric valve in which a needle valve (4) controls a small flow rate, the maximum flow rate in the small flow rate control region is suppressed from deviating, and the controllable range in the small flow rate control region is made large. The needle valve (4) having a second conical frustum portion (44) in which the diameter gradually decreases toward the front end is disposed on the axis L of the sub valve port (33a). The needle valve (4) is moved in and out on the axis by a driving portion (5). The small flow rate control region is obtained by the needle valve (4) and the sub valve port (33a). The large flow rate control region is obtained by the main valve core (3) and the main valve port (13a). A second straight portion (45) having a constant diameter is provided in connection with the smallest diameter portion of the second conical frustum portion (44) of the needle valve (4). The second straight portion (45) is kept inside the sub valve port (33a) at the position where the second conical frustum portion (44) is withdrawn from the sub valve port (33a).

This application discloses a start / stop drain pipe heat tracing device, relating to the field of heating pipe networks. It includes an inlet pipe connected to the main pipe of the heating pipe network. Below the inlet pipe, a first drain valve, a relay pipe, a second drain valve, and an outlet pipe are connected in sequence. A branch pipe is connected to the side end of the relay pipe, and a needle valve is connected to the end of the branch pipe. A flexible metal hose is installed at the rear end of the needle valve, and the flexible metal hose is sequentially wound around the relay pipe, the second drain valve, and the outlet pipe. This device can achieve a steam heat tracing effect by slightly opening the needle valve, allowing a very small amount of steam to flow through the flexible metal hose. A small amount of steam also flows through the inlet pipe to maintain a certain temperature, saving steam and solving the problem of easy damage to the start / stop drain valve, ensuring the integrity of the equipment and ensuring the effective implementation of cold-proof and anti-freezing measures.

This invention provides a swirl-atomizing urea injector, comprising at least a nozzle needle valve assembly, an injection-molded connector assembly, a solenoid valve assembly, an outer cover, and a sealing ring. The nozzle needle valve assembly includes a filter screen, an upper nozzle body, a spring retaining ring, a needle valve spring, a lower nozzle body, a needle valve, a valve seat, a valve seat mounting plate, and a swirl orifice plate. The swirl orifice plate has several swirl grooves connected to a central countersunk hole and an outer countersunk hole. The long side of the swirl groove is tangent to the outer circle of the outer countersunk hole, and the short side of the swirl groove intersects the outer circle of the outer countersunk hole, with its extension trajectory passing through the center of the outer countersunk hole. The bottom surface of the swirl groove forms a certain angle with the surface of the swirl orifice plate. The width of the swirl groove gradually narrows from the first end to the second end, and the depth gradually decreases. When the urea aqueous solution passes through the swirl groove, it can be further accelerated and form a swirl. This invention has the advantages of reducing spray particle size, improving urea injection atomization effect, and reducing the risk of urea crystallization in diesel engine aftertreatment.

This invention belongs to the technical field of oilfield production equipment and relates to a digital anti-theft needle valve, including a contact needle and a first micro-switch. The bottom of the contact needle is connected to the trigger end of the first micro-switch, and the upper end of the contact needle passes through a through hole. The top of the contact needle is not lower than the upper opening of the through hole. The bottom of a ball rolls around the upper surface of a step. The upper opening of the through hole is located on the rolling path of the ball. When the handwheel is rotated, causing the ball to roll along the upper surface of the step, the ball will press the top of the contact needle, causing the contact needle to slide downward and press the trigger end of the first micro-switch to issue an alarm. This invention can promptly detect theft by criminals, has a significant deterrent effect, fundamentally solves the problem of sampling valves being easily stolen, and ensures the safety and economic benefits of oilfield crude oil.

This utility model relates to the field of needle valve processing technology, and in particular to a vibratory drilling equipment for processing diesel engine needle valves. The technical solution includes a processing table, with a guide plate fixed to the top of the processing table. A sliding sleeve is slidably connected to one side of the guide plate. The sliding sleeve is connected to the inside of the guide plate via a hydraulic rod. This utility model, by setting a driving structure, can move two sets of clamps towards the center, thereby fixing the position of the needle valve body. Subsequently, the needle valve body is processed by a drilling machine. A collection tank inside the clamps can collect the cutting fluid and metal chips generated during drilling. A collection box is provided, and multiple sets of filter holes at the bottom of the collection box can isolate the metal chips within the collection box, while allowing the cutting fluid to flow into the bottom of the collection tank. This allows for separate collection of metal chips and cutting fluid, facilitating subsequent classification and processing, and solving the problem of inconvenient collection of cutting fluid and chips during needle valve drilling.

This invention belongs to the field of oil and gas reservoir drainage and gas production, specifically relating to a flameless low-temperature catalytic needle valve insulation box device. It aims to solve the problem of hydrate formation at the needle valve, causing blockage. The invention includes at least one needle valve insulation box, an electric heating component, a low-temperature catalytic reaction plate, and a gas source pipeline. The electric heating component and the low-temperature catalytic reaction plate are disposed within the needle valve insulation box. One end of the gas source pipeline is connected to a gas well, and the other end extends into the needle valve insulation box. The electric heating component heats the low-temperature catalytic reaction plate to the reaction temperature. The gas source pipeline supplies natural gas and air to the needle valve insulation box. Under the action of the low-temperature catalytic reaction plate, the natural gas and air undergo a catalytic oxidation reaction and continuously release heat, thus solving the problem of hydrate formation at the needle valve causing blockage.

An adjustment method for a shut-off nozzle provided in an injection device, the shut-off nozzle including a nozzle portion having an injection flow path and a needle hole, a needle valve movably insertable into the needle hole, a cylinder component driving the needle valve, a bracket rotatably support the cylinder component at a rear end, and a fixing device fixing the bracket to a fixing member of the injection device, the adjustment method including: releasing the fixing device to allow the bracket to slide by a predetermined width relative to the fixing member, heating the injection device and the nozzle portion, driving the cylinder component to bring the needle valve to a most forward position and adjusting a slide position of the bracket, and fastening the fixing device to fix the bracket to the fixing member.

The purpose of this invention is to provide a high-response, low-return injector based on a two-position three-way valve, belonging to the field of engine technology. It includes a fastening cap, a two-position three-way solenoid valve module, an injector body, and a nozzle. The injector body has a needle valve and a fuel injection channel. A control chamber is formed between the top of the needle valve and the two-position three-way solenoid valve. An injection orifice is opened at the lower end of the nozzle. The two-position three-way solenoid valve module consists of a ball valve and a cone valve, connected by a transmission spring. It utilizes the advantages of the ball valve (good dynamic sealing and self-centering) and the cone valve (suitable for high-flow sealing), allowing for independent inlet and outlet processes in the control chamber to reduce return flow and accelerate needle valve opening. Compared to a two-position three-way valve with a double cone valve design, it requires lower machining precision. Furthermore, this invention is equipped with a large-sized control chamber throttling orifice and return orifice to further improve the injector's opening and closing response, making it suitable for engines or industrial equipment requiring rapid start / stop and precise flow control.

The invention relates to a high-pressure valve arrangement (1) comprising a valve block (2), wherein a needle valve (6) is arranged in the valve block (2) and the needle valve (6) is displaceable in the axial direction (A) via an actuator, such that a supply channel (3) and a discharge channel (4) in the valve block (2) are fluidly connected to each other in an open position via a valve seat (7) of the needle valve (6) and are separated from each other in a closed position of the needle valve (6), wherein a sleeve-shaped receptacle (9) for a valve stem (10) of the needle valve (6) is located at an axial end of the actuator, characterized in that the sleeve-shaped receptacle (9) has three balls (12) extending radially around it, which engage section by section in a radially circumferential groove (13) of the valve stem (10) and are mounted in a radially circumferential inner running surface (14) of the valve block (2) or actuator.

This utility model relates to the field of gas valve technology and discloses a needle valve that facilitates linear flow regulation. It includes a valve body, a valve seat fixedly mounted on the valve body, and a valve stem movably inserted into the valve seat. The valve body has an inlet and an outlet at both ends. The inlet is connected to an inlet channel within the valve body, and the outlet is connected to an outlet channel within the valve body. The valve seat has a cavity that communicates with both the inlet and outlet channels. One end of the valve stem extends out of the valve seat, and the other end passes through the cavity and is inserted into the valve body. A needle-shaped adjusting post is provided at the end of the valve stem. An adjusting sealing cavity is provided within the valve body. The needle-shaped adjusting post is adapted to the adjusting sealing cavity. The outer circumferential surface of the needle-shaped adjusting post is conical. The needle-shaped adjusting post is inserted into the adjusting sealing cavity to seal the inlet and outlet channels.

The application relates to a hot nozzle structure capable of avoiding hidden glue behind a valve needle, and relates to the technical field of hot runner molds. The hot nozzle structure capable of avoiding hidden glue behind a valve needle comprises a flow distribution plate, a main nozzle, a nozzle body, a valve needle and a flow guide shuttle. A first flow channel allowing glue flow is arranged in the flow distribution plate. The main nozzle is used for injecting molten glue. The main nozzle is abutted on the first flow channel from the first surface of the flow distribution plate. The nozzle body is arranged on the second surface of the flow distribution plate. A second flow channel is arranged in the nozzle body. The second flow channel is communicated with the first flow channel. The valve needle is arranged in the nozzle body and penetrates through the nozzle body and the flow distribution plate. The flow guide shuttle is sleeved on the valve needle. The flow guide shuttle comprises a connecting part in a cylindrical shape and a flow guide part arranged on the outer sidewall of the connecting part. The flow guide part is arranged in a spiral structure and used for improving the flowability of the glue.

The utility model discloses a blast furnace top gas analysis system with voltage stabilization and protection, belonging to the technical field of chemical waste gas detection and analysis. The system includes a sampling device, a pretreatment module, and a gas analyzer. After the sampling device collects the blast furnace gas, the sampled gas is transported to the gas analyzer through the pretreatment module. The pretreatment module includes a voltage stabilization unit. The structure of the voltage stabilization unit includes a pressure gauge for collecting the pressure of the sampled gas before entering the filter. The output end of the filter is connected with a pneumatic switching valve. The conveying pipeline of the sampled gas of the pneumatic switching valve is at least divided into two paths. One path is directly connected to a pressure stabilizing valve, and the other path enters the pressure stabilizing valve after passing through an air extraction pump and a check valve in sequence. A needle valve is connected in parallel with the air extraction pump, and the needle valve and the air extraction pump form a sampled gas loop. The pressure gauge is connected with a PLC controller, and the PLC controller controls the pneumatic switching valve by controlling an electromagnetic valve. The utility model has the characteristics of voltage stabilization and safety.

This application relates to the technical field of needle valve assembly processing, and discloses an automatic tray-loading device for needle valve assemblies, including a vibratory plate and a mounting base. A turntable is rotatably mounted on the mounting base, and a power source is installed on the mounting base to drive the turntable to rotate at intervals. The vibratory plate is connected to a conveying channel, and a discharge section is provided within the vibratory plate for only one needle valve assembly to pass through. The discharge section is connected to the conveying channel. The turntable has an installation area for mold installation, and one end of the conveying channel is close to the installation area. The device also includes a sliding assembly, which includes a guide rail and a drive source. The mounting base is slidably mounted on the guide rail, and the drive source is connected to the mounting base. Furthermore, it includes a CNC system for controlling the opening and closing of the power source and the drive source. This application can automatically control the needle valve assembly to gradually fill the entire mold through the CNC system.

A tail gas absorption device, including absorption bucket, absorption bucket is used for containing substance for absorbing tail gas, the top of absorption bucket is detachable with top cover, top cover is through type setting has tail gas connecting pipe, tail gas connecting pipe is provided with needle valve, absorption bucket is placed on walking mechanism, the beneficial effects of the utility model are: (1) prevent tail gas from escaping, reduce environmental pollution and the health damage to the operator; (2) absorption bucket is placed on walking mechanism, it is convenient to move between multiple tail gas sampling points, and single person can promote device movement, improve tail gas absorption efficiency; (3) compared with traditional manual replacement mode, can reduce absorption liquid waste, at the same time avoid the absorption efficiency decline caused by absorption liquid failure; (4) bottom plate positioning groove and absorption bucket bottom shape match, prevent device from shaking when moving through friction and limiting structure; avoid personnel to cause scald or corrosive injury by mistake absorption bucket, prevent absorption bucket from toppling over in the transportation process simultaneously.

This utility model discloses an injector and an engine. The injector includes a valve body and a first needle valve. The valve body has a first cavity, a first nozzle, and a first chamber. One end of the first nozzle communicates with the first chamber, and the other end communicates with the outside of the valve body. The first needle valve is located in the first cavity. When the first needle valve is in a first position, the outer wall of the first needle valve contacts the inner wall of the valve body to form a first contact portion and a second contact portion. The outer wall of the first needle valve located between the first contact portion and the second contact portion and the inner wall of the valve body defines a second chamber, which communicates with the first chamber. The injector has a small dimension in the axial direction of the first nozzle, which not only avoids the first fuel flowing back along the first nozzle and causing erosion of the first needle valve, but also reduces the length-to-diameter ratio and penetration distance of the first nozzle, reducing the risk of first fuel adhering to the wall. This reduces the failure probability of the injector and the engine, and improves the reliability of the injector and the engine.

The utility model relates to hot runner needle valve technical field discloses a kind of cylindrical valve needle guide ring, including nozzle sleeve, the inner wall sliding connection of nozzle sleeve has valve needle guide ring, the inner wall sliding connection of valve needle guide ring has valve needle, the inner wall of nozzle sleeve is equipped with nozzle sleeve kit, the outer wall of nozzle sleeve kit is equipped with connecting piece, the outer wall of valve needle is provided with multiple stabilizing blocks one, the inner wall of nozzle sleeve is provided with multiple stabilizing blocks two, the inner wall of valve needle guide ring is equipped with multiple stabilizing grooves one, the outer wall of valve needle guide ring is equipped with multiple stabilizing grooves two, the top of valve needle guide ring is equipped with cleaning assembly, the inner wall of valve needle guide ring is provided with lubricating assembly, in the utility model, four stabilizing grooves one are set in valve needle guide ring inner wall, four valve needle guide rings are set in valve needle guide ring outer wall, let stabilizing block one and stabilizing block two respectively be clamped in stabilizing groove one and stabilizing groove two inner wall, reach the effect that valve needle is stably slid up and down.

This utility model discloses an injection mold that prevents products from sticking to the front mold. It includes a front mold mechanism and a rear mold mechanism. The front mold mechanism includes a front top plate, a front mold plate, a front mold core, a hot runner needle valve assembly, and an air ejector device. The rear mold mechanism includes a rear mold plate, a rear mold core, and several undercut pins. A sprue is provided at the sprue port on the front top plate. The hot runner needle valve assembly is installed inside the front mold plate and communicates with the sprue. The front and rear mold cores cooperate to form a mold cavity. Each needle valve nozzle of the hot runner needle valve assembly extends into the mold cavity. The air ejector device includes an air pipe and an air nozzle. Each air pipe's outlet end is equipped with an air nozzle, each pointing downwards and corresponding to the mold cavity. The undercut end of each undercut pin extends upwards through the top surface of the rear mold core and into the mold cavity. This utility model achieves balanced demolding without product dragging through the synergistic effect of front mold air ejection and rear mold undercut pins, improving product yield.