Protection type valve rod protection structure and thermostat

Abstract

The invention discloses a protection type valve rod protection structure and a thermostat, and belongs to the technical field of thermostats, the protection type valve rod protection structure comprises a shell, a valve seat, a push rod, a temperature sensing element and a protection sleeve; the shell forms a main body of the thermostat, and a cooling liquid flow channel is formed in the shell; the protective sleeve is of a cylindrical structure and is fixedly arranged on the periphery of the push rod in a sleeving mode, the outer wall face of the protective sleeve is fixed to the valve seat in a sealed mode, and the length of the protective sleeve at least covers the portion, located in the guide hole and exposed in the cooling liquid flow channel, of the push rod. The special protective sleeve is additionally arranged on a key moving part, namely the push rod, so that the body of the push rod is always and effectively isolated from external cooling liquid and impurities such as rust, water scale and casting sand carried in the body of the push rod in dynamic movement; direct attachment and clamping stagnation of foreign matter are avoided, hard particles in cooling liquid cannot make direct contact with the surface of the push rod, the hard particles are prevented from being embedded into a tiny gap between the push rod and the guide hole, and therefore the working reliability of the thermostat is greatly improved, and the service life of the thermostat is greatly prolonged.

Description

Technical Field

[0001] This invention relates to the field of thermostat technology, and in particular to a protective valve stem protection structure and a thermostat. Background Technology

[0002] As a core regulating component in the engine cooling system, the thermostat's main function is to automatically control the flow path and flow rate of the coolant based on changes in coolant temperature, thereby ensuring that the engine always operates within a suitable temperature range. Traditional thermostats typically consist of a housing, valve seat, push rod, temperature-sensing element, and valve. Its working principle is as follows: the temperature-sensing element (such as temperature-sensitive wax or shape memory alloy) undergoes a change in volume or shape when heated, generating axial thrust. This drives the push rod to move along the guide hole of the valve seat, thereby opening or closing the valve and regulating the coolant passage. This simple structure and rapid response have long been widely used in various internal combustion engine cooling systems, providing a fundamental guarantee for engine thermal management.

[0003] In actual operation, especially in engine cooling systems that operate under complex conditions for extended periods, the thermostat's valve stem often faces a harsh working environment. As a critical moving component, the pushrod is typically directly exposed to the circulating coolant, which often contains various impurities resulting from system aging, corrosion, or lack of timely maintenance, such as rust, scale, and casting residue. These impurities easily adhere to the pushrod surface or become embedded in the tiny gaps between the pushrod and the guide hole, causing the pushrod to jam, become obstructed, or even completely seize during movement, severely affecting the thermostat's response accuracy and operational reliability. Simultaneously, the high-speed flow of coolant within the system creates continuous hydraulic impact on the pushrod surface, which over time can cause wear, scratches, or pitting, reducing its smoothness of movement and sealing performance, thereby shortening the overall service life of the thermostat.

[0004] Therefore, it is necessary to provide a protective valve stem protection structure and a thermostat to solve the above-mentioned technical problems. Summary of the Invention

[0005] The purpose of this invention is to provide a protective valve stem protection structure and a thermostat to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following solution to the aforementioned technical problems: a protective valve stem protection structure and thermostat, comprising: a housing, a valve seat, a push rod, a temperature sensing element, and a protective sleeve; the housing constitutes the main body of the thermostat, and a coolant flow channel is formed inside it; the valve seat is fixedly disposed inside the housing and has a valve port thereon; the push rod is axially movably inserted through the valve seat, one end of which is connected to the temperature sensing element, and the other end is connected to or constitutes a valve for opening and closing the valve port; the temperature sensing element is disposed inside the housing and is used to respond to changes in coolant temperature and drive the push rod to move axially; the protective sleeve is a cylindrical structure, which is sleeved and fixed to the outer periphery of the push rod, and the outer wall surface of the protective sleeve is sealed and fixed to the valve seat, and the length of the protective sleeve at least covers the portion of the push rod located in the guide hole and exposed in the coolant flow channel.

[0007] As a further embodiment of the present invention, one end of the protective sleeve is fixedly connected to the outer surface of the push rod by an interference fit.

[0008] As a further embodiment of the present invention, the protective sleeve is made of an elastic material that is corrosion-resistant, wear-resistant, and compatible with coolant.

[0009] As a further embodiment of the present invention, at least one annular sealing groove is provided on the outer wall surface of the protective sleeve, and an elastic sealing ring is embedded in the annular sealing groove, the elastic sealing ring being in interference contact with the inner wall of the guide hole of the valve seat.

[0010] As a further embodiment of the present invention, the protective sleeve has a radially outwardly extending annular shoulder at one end near the temperature sensing element, the valve seat end is provided with a spring, and the outer shell is connected to a pipeline.

[0011] As a further embodiment of the present invention, the annular shoulder and the protective sleeve are integrally formed.

[0012] As a further embodiment of the present invention, the protective sleeve is generally gourd-shaped.

[0013] As a further aspect of the present invention, a thermostat includes a protective valve stem protection structure.

[0014] Compared with the prior art, the beneficial effects of the present invention are:

[0015] A special protective sleeve is installed on the key moving component, the push rod. During dynamic movement, this sleeve effectively isolates the push rod body from the external coolant and impurities it carries, such as rust, scale, and casting sand. This prevents direct adhesion and jamming of foreign objects, and hard particles in the coolant cannot directly contact the push rod surface, avoiding their embedding in the tiny gap between the push rod and the guide hole. This completely eliminates the risk of push rod movement jamming, obstruction, or even seizure caused by foreign objects, significantly improving the thermostat's reliability and service life. Secondly, it effectively resists water flow impact and cavitation erosion. Under high-speed coolant flow conditions, the protective sleeve, as a more integral cylindrical surface, replaces the push rod itself in bearing the frontal impact of the fluid and the potential impact of cavitation bubble collapse. This protects the push rod's surface finish, preventing wear, scratches, or pitting caused by long-term water impact, ensuring the smoothness and accuracy of the push rod's movement. With its compact structure and high integration, it does not require changes to the main layout and external dimensions of the thermostat, making it easy to improve and integrate with existing thermostat products. The modification cost is low and its promotion is highly feasible. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0017] Figure 1 The overall three-dimensional structure of the present invention Figure 1 ;

[0018] Figure 2 The overall three-dimensional structure of the present invention Figure 2 ;

[0019] Figure 3 The overall three-dimensional structure of the present invention Figure 3 ;

[0020] Figure 4 This is a schematic diagram of the gourd-shaped protective sleeve of the present invention when it is opened;

[0021] Figure 5 This is a schematic diagram of the gourd-shaped protective sleeve of the present invention when closed;

[0022] Figure 6 This is a schematic diagram of the disc-shaped protective sleeve of the present invention when it is opened;

[0023] Figure 7 This is a schematic diagram of the disc-shaped protective sleeve of the present invention when closed;

[0024] Figure 8 This is a schematic diagram of the gourd-shaped protective sleeve structure of the present invention;

[0025] Figure 9 This is a schematic diagram of the disc-shaped protective sleeve structure of the present invention.

[0026] The attached diagram lists the components represented by each number as follows:

[0027] 1. Housing; 2. Valve seat; 3. Push rod; 4. Temperature sensing element; 5. Protective sleeve; 6. Spring; 31. Valve; 7. Pipeline. Detailed Implementation

[0028] The present invention will be further described below with reference to embodiments.

[0029] Please see Figure 1-9 This invention provides a protective valve stem protection structure and thermostat, comprising: a housing 1, a valve seat 2, a push rod 3, a temperature sensing element 4, and a protective sleeve 5; the housing 1 constitutes the main body of the thermostat, and a coolant flow channel is formed inside it; the valve seat 2 is fixedly disposed inside the housing 1, and has a valve port thereon; the push rod 3 is axially movably inserted through the valve seat 2, one end of which is connected to the temperature sensing element 4, and the other end is connected to or constitutes a valve 31 for opening and closing the valve port; the temperature sensing element 4 is disposed inside the housing 1, and is used to respond to changes in coolant temperature and The push rod 3 moves axially; the protective sleeve 5 is a cylindrical structure, which is sleeved and fixed to the outer periphery of the push rod 3, and the outer wall of the protective sleeve 5 is sealed and fixed to the valve seat 2. The length of the protective sleeve 5 at least covers the part of the push rod 3 located in the guide hole and exposed in the coolant flow channel; when the engine coolant temperature rises, the temperature sensing element 4 (such as temperature sensing wax or shape memory alloy) expands due to heat, generating axial thrust, driving the push rod 3 to move to one side, thereby driving the valve 31 to open or change its opening degree, increasing the amount of coolant passing through the valve port. The flow rate is increased to enhance heat dissipation, and the process reverses when the temperature decreases. A special protective sleeve 5 is installed on the key moving component, push rod 3. During dynamic movement, it effectively isolates the body of push rod 3 from the external coolant and impurities such as rust, scale, and casting sand particles. This avoids direct adhesion and jamming of foreign objects, and prevents hard particles in the coolant from directly contacting the surface of push rod 3, thus avoiding their embedding in the tiny gap between push rod 3 and guide hole. This completely eliminates the risk of push rod 3 getting stuck, blocked, or even jammed due to foreign objects, significantly improving the reliability and service life of the thermostat. Secondly, it effectively resists water flow impact and cavitation erosion. Under the condition of high-speed coolant flow, the protective sleeve 5, as a more integral cylindrical surface, replaces push rod 3 itself in bearing the frontal impact of the fluid and the possible impact of cavitation bubble collapse. This protects the surface smoothness of push rod 3 and prevents wear, scratches, or pitting caused by long-term water impact, ensuring the smoothness and accuracy of push rod 3's movement. With its compact structure and high integration, it does not require changes to the main layout and external dimensions of the thermostat, making it easy to improve and integrate with existing thermostat products. The modification cost is low and its promotion is highly feasible.

[0030] It is worth further elaborating that one end of the protective sleeve 5 is fixedly connected to the outer surface of the push rod 3 through an interference fit. When using an interference fit, the inner diameter of the protective sleeve 5 is designed to be slightly smaller than the outer diameter of the corresponding position of the push rod 3. It is then assembled by pressure to tightly hug the push rod 3. The fixation is achieved by the radial pressure generated by the elasticity of the material, ensuring that the protective sleeve 5 can form a solid moving whole with the push rod 3. Under various working conditions, there will be no relative displacement or detachment, thus ensuring that the protective sleeve 5 can accurately follow the movement of the push rod 3.

[0031] It is worth further elaborating that the protective sleeve 5 is made of an elastic material that is corrosion-resistant, wear-resistant, and compatible with coolant. The material of the protective sleeve 5 is preferably rubber or elastic plastic, which can balance strength, rigidity, wear resistance, and cost according to requirements. The material itself has moderate hardness and low coefficient of friction. Its excellent corrosion resistance allows it to withstand antifreeze, additives, and acidic substances that may be contained in the engine coolant and that may be produced due to system aging for a long time without swelling, degradation, or decrease in strength, thus ensuring the durability of the protection.

[0032] It is worth further elaborating that the outer wall of the protective sleeve 5 is provided with at least one annular sealing groove, and an elastic sealing ring is embedded in the annular sealing groove. The elastic sealing ring is in interference contact with the inner wall of the guide hole of the valve seat 2. By adding one or more elastic sealing rings made of elastic material at the sliding interface between the protective sleeve 5 and the guide hole, the sealing ring is installed in the annular sealing groove of the protective sleeve. Since its outer diameter in its natural state is larger than the inner diameter of the guide hole, it is in a compressed state after installation, thereby generating a continuous elastic restoring force in the radial direction, tightly adhering to the inner wall of the guide hole, forming a dynamic seal. The elastic sealing ring can effectively prevent coolant and its tiny particles from intruding into the surface of the push rod 3 through the fit gap between the protective sleeve 5 and the guide hole. Even if the outer wall of the protective sleeve 5 is slightly worn after long-term use, the elasticity of the sealing ring can compensate for the gap and maintain the sealing effect. At the same time, the appropriate compression of the sealing ring can further provide a certain amount of damping, which helps to reduce the impact of the push rod 3 at the moment of opening and closing, making the valve operation smoother.

[0033] It is worth further elaboration that the protective sleeve 5 has a radially outwardly extending annular shoulder at the end near the temperature sensing element 4, the valve seat 2 has a spring 6 at the end, and the outer shell 1 is connected to a pipe 7.

[0034] It is worth further elaborating that the annular shoulder and the protective sleeve 5 are integrally formed. The annular shoulder provides a stable support surface. There is no mechanical connection interface between the annular shoulder and the protective sleeve 5 cylinder. The material itself continuously transmits the material to the entire protective sleeve 5 cylinder, which is suitable for harsh environments with high vibration and high load. At the same time, the integral forming ensures the perpendicularity of the end face of the annular shoulder to the axis of the protective sleeve 5, which is beneficial to the stability of the sliding seal.

[0035] Further as Figure 1 , Figure 2 and Figure 3 As shown, it is worth noting that the protective sleeve 5 is as follows: Figure 8 gourd-shaped or Figure 9 The disc-shaped design, with its unique "expanded ends and tapered middle" contour, achieves multiple optimizations. The narrowed "waistline" in the middle ensures a firm connection with the push rod while reducing the contact area with the guide hole, thus significantly reducing sliding friction resistance and wear, making the valve stem movement more sensitive and smooth. The expanded ends enhance structural rigidity and provide a stable support surface, which is beneficial for guiding the coolant flow, reducing turbulence and local impact pressure, and further improving the resistance to fluid impact and cavitation.

[0036] A thermostat includes a protective valve stem protection structure. The thermostat using the aforementioned protective valve stem protection structure can easily cope with harsh operating conditions such as inferior coolant, serious pollution caused by long-term non-replacement, and violent fluctuations in the cooling system. It solves the industry problem of valve stem jamming in traditional thermostats and is particularly suitable for applications in commercial vehicles, construction machinery, generator sets, and harsh environments where reliability requirements are extremely high.

[0037] In summary: By installing a dedicated protective sleeve 5 on the key moving component, push rod 3, it effectively isolates the push rod 3 from the external coolant and impurities such as rust, scale, and casting sand during dynamic movement. This prevents direct adhesion and jamming of foreign objects, and hard particles in the coolant cannot directly contact the surface of push rod 3, thus avoiding their embedding in the tiny gap between push rod 3 and guide hole. This completely eliminates the risk of push rod 3 becoming stuck, obstructed, or even jammed due to foreign objects, significantly improving the reliability and service life of the thermostat. Secondly, it effectively resists water flow impact and cavitation erosion. Under high-speed coolant flow conditions, the protective sleeve 5, as a more integral cylindrical surface, replaces push rod 3 itself in bearing the frontal impact of the fluid and the impact of possible cavitation bubble collapse. This protects the surface finish of push rod 3, preventing wear, scratches, or pitting caused by long-term water impact, and ensuring the smoothness and accuracy of push rod 3's movement. With its compact structure and high integration, it does not require changes to the main layout and external dimensions of the thermostat, making it easy to improve and integrate with existing thermostat products. The modification cost is low and its promotion is highly feasible.

Claims

1. A protective valve stem protection structure, characterized in that, include: The device comprises a housing (1), a valve seat (2), a push rod (3), a temperature sensing element (4), and a protective sleeve (5). The housing (1) forms the main body of the thermostat, and a coolant flow channel is formed inside it. The valve seat (2) is fixedly installed inside the housing (1) and has a valve port. The push rod (3) is axially movable through the valve seat (2), with one end connected to the temperature sensing element (4) and the other end connected to or forming a valve (31) for opening and closing the valve port. The temperature sensing element (4) is installed inside the housing (1) and is used to respond to changes in coolant temperature and drive the push rod (3) to move axially. The protective sleeve (5) is a cylindrical structure that is fitted and fixed to the outer periphery of the push rod (3), and the outer wall of the protective sleeve (5) is sealed and fixed to the valve seat (2). The length of the protective sleeve (5) covers at least the portion of the push rod (3) located in the guide hole of the valve seat (2) and exposed in the coolant flow channel.

2. The protective valve stem protection structure according to claim 1, characterized in that: One end of the protective sleeve (5) is fixedly connected to the outer surface of the push rod (3) by an interference fit.

3. The protective valve stem protection structure according to claim 2, characterized in that: The protective sleeve (5) is made of an elastic material that is corrosion-resistant, wear-resistant and compatible with coolant.

4. The protective valve stem protection structure according to claim 3, characterized in that: The outer wall of the protective sleeve (5) is provided with at least one annular sealing groove, and an elastic sealing ring is embedded in the annular sealing groove. The elastic sealing ring is in interference contact with the inner wall of the guide hole of the valve seat (2).

5. A protective valve stem protection structure according to claim 4, characterized in that: The protective sleeve (5) has a radially outwardly extending annular shoulder at one end near the temperature sensing element (4), the valve seat (2) has a spring (6) at its end, and the outer shell (1) is connected to a pipe (7).

6. The protective valve stem protection structure according to claim 5, characterized in that: The annular shoulder and the protective sleeve (5) are integrally formed.

7. The protective valve stem protection structure according to claim 1, characterized in that: The protective sleeve (5) is generally gourd-shaped.

8. A thermostat, characterized in that, Includes the protective valve stem protection structure as described in any one of claims 1 to 7.

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