JP2009221901A - Diaphragm for metering pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metallic diaphragm for a metering pump having a low Young's modulus and high elastic deformability. <P>SOLUTION: The diaphragm for the metering pump capable of transferring a fluid by predetermined elastic deformation is formed of a highly elastically-deformable titanium alloy which: comprises a 30-60 mass%, group Va (vanadium group) element and the substantial balance of titanium; has a tensile elasticity limit of 700 MPa or more, defined as a stress applied when permanent deformation truly reaches 0.2% at a tensile test; exhibits a characteristic that, within an elastic deformation region where the stress to be applied ranges from 0 to the tensile elastic limit strength, the slope of a tangent on a stress-strain diagram obtained by the tensile test decreases with the increase in stress; and has an average Young's modulus of 75 GPa or less obtained from the slope of the tangent at a stress position corresponding to 1/2 of the tensile elastic limit strength as a typical value of Young's moduli obtained from the slope of the tangent on the stress-strain diagram. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a metal diaphragm that is used in a metering pump and conveys a predetermined fluid by elastic deformation by a predetermined pressure.

  Conventionally, for example, as a metering pump (reciprocating pump), a pump head, a diaphragm, a piston portion provided on the diaphragm, and a drive source for driving the piston portion are provided, and the piston portion is driven by the drive source. In some cases, a predetermined fluid (for example, gas or liquid) is conveyed by periodically reciprocating the diaphragm (see, for example, Patent Document 1).

In such a pump, for example, when the fluid to be conveyed is a liquid containing an oxidizing substance such as an alkaline hypochlorite aqueous solution, the diaphragm is made of a synthetic resin in consideration of corrosion resistance. Is often used.
JP 2006-207533 A

  In addition to a conventional resin diaphragm, a metal diaphragm may be used from the viewpoint of good strength, durability, and workability.

  However, when the diaphragm is made of metal, it is less likely to be elastically deformed than a resin diaphragm. Therefore, in order to construct a pump having the same discharge amount as a resin diaphragm, this metal There was a problem that the diaphragm was increased in size and the pump was increased in size.

  Therefore, in order to reduce the size of a pump using a metal diaphragm, it is necessary to reduce the Young's modulus of the diaphragm and improve the elastic deformability.

  Therefore, an object of the present invention is to provide a metal metering pump diaphragm having a low Young's modulus and a high elastic deformability.

  In order to solve the above problems, the present invention has taken the following technical means.

  That is, the present invention is a diaphragm for a metering pump capable of conveying a fluid by a predetermined elastic deformation, comprising 30 to 60% by mass of a Va group (vanadium group) element, and the balance being substantially titanium, In the elastic deformation region where the tensile elastic limit strength defined as the stress when the permanent set reaches 0.2% in the test is 700 MPa or more and the applied stress is in the range from 0 to the tensile elastic limit strength. As a representative value of Young's modulus obtained from the slope of the tangent on the stress-strain diagram, which shows a characteristic that the slope of the tangent on the stress-strain diagram obtained by the tensile test decreases as the stress increases. The titanium alloy is characterized by being formed of a titanium alloy having a high elastic deformability having an average Young's modulus of 75 GPa or less determined from a slope of a tangent at a stress position corresponding to 1/2 of the tensile elastic limit strength.

  Such a diaphragm for a metering pump according to the present invention exhibits a novel characteristic that has never existed in the past, in which the slope of the tangent line on the stress-strain diagram decreases as the stress increases within the elastic deformation region. Is made of a highly elastic deformable titanium alloy having a high elastic strength of 700 MPa or more and a low Young's modulus of an average Young's modulus of 75 GPa or less. As a result, the diaphragm can realize desired elastic deformation without extremely increasing its size.

  In addition, the diaphragm for a metering pump according to the present invention can obtain a high elastic deformability and high strength with a low Young's modulus, which is unprecedented, by constituting a titanium alloy with a combination of titanium and an appropriate amount of Va group element. Is. Here, the reason why the Va group element is set to 30 to 60% by mass is that if the amount is less than 30% by mass, the average Young's modulus cannot be sufficiently reduced, whereas if it exceeds 60% by mass, sufficient elastic deformability and tensile strength are obtained. This is because the density of the titanium alloy is increased and the specific strength is lowered. On the other hand, if it exceeds 60% by mass, material segregation is likely to occur, the homogeneity of the material is impaired, and not only strength but also toughness and ductility are easily lowered.

  In the present invention, the “titanium alloy” means an alloy containing Ti, and does not specify the content of Ti. “Tensile elastic limit strength” refers to the load applied when the permanent elongation (strain) reaches 0.2% in a tensile test in which loading and unloading of the test piece are repeated gradually. Stress. In this respect, the tensile test is different from the tensile strength obtained by dividing the load immediately before the final break of the test piece by the cross-sectional area before the test in the parallel portion of the test piece.

  The “average Young's modulus” does not mean the “average” of Young's modulus in a strict sense, but means the Young's modulus representing the titanium alloy used in the present invention. Specifically, in the stress (load) -strain (elongation) diagram obtained by the tensile test, the slope (tangential slope) of the curve at the stress position corresponding to 1/2 of the tensile elastic limit strength, The average Young's modulus was used. In the present specification, “low Young's modulus” means that the average Young's modulus is smaller than the conventional general Young's modulus, and “high strength” means the tensile elastic limit strength or It means that the tensile strength is large.

  The diaphragm for a metering pump according to the present invention is formed in a circular shape, and has a configuration in which 0.0003 ≦ t / D ≦ 0.02 when the thickness is t and the diameter is D. Can be adopted.

  According to this configuration, the diaphragm for the metering pump can appropriately transport the transport fluid by desired elastic deformation. If the diaphragm is too thin with respect to its diameter (t / D becomes smaller than 0.0003), the pressure resistance is lowered, which is not preferable. On the other hand, when the thickness is too thick with respect to the diameter (when t / D is larger than 0.02), the elastic deformability of the diaphragm is lowered, and a sufficient discharge amount cannot be secured, which is not preferable.

  Moreover, the diaphragm for metering pumps according to the present invention can employ a configuration in which the outer edge portion is thicker than the central portion.

  According to such a configuration, when the diaphragm is attached to the metering pump (reciprocating pump), for example, if the outer edge portion having a thick thickness is sandwiched, the diaphragm is fixed without impairing the elastic deformability of the central portion. This thick portion can be securely and firmly fixed to the pump (reciprocating pump), and its sealing performance is also greatly improved.

  Moreover, the diaphragm for metering pumps according to the present invention can employ a configuration in which the thickness of the outer edge portion is at least three times the thickness of the central portion.

  According to such a configuration, when the diaphragm is attached to the metering pump (reciprocating pump), for example, if the outer edge portion having a thick thickness is sandwiched, the diaphragm is fixed without impairing the elastic deformability of the central portion. With respect to the pump (reciprocating pump), this thick portion can be fixed securely and firmly, and the sealing performance is also greatly improved.

  Moreover, the diaphragm for metering pumps according to the present invention can employ a configuration in which the outer edge portion is formed in an annular shape from the titanium alloy or metal titanium.

  According to such a configuration, the outer edge portion of the diaphragm is made of the titanium alloy or metal titanium, so that the physical properties (for example, thermal expansion coefficient) of the outer edge portion are the same as or close to the central portion. As a result, the durability and the like are good and the manufacture thereof is facilitated.

  According to the present invention, a metal diaphragm having a low Young's modulus and a high elastic deformability can be provided.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings. FIG. 1 is a schematic sectional view of a metering pump (reciprocating pump) as an example using the diaphragm according to the present invention.

  As shown in FIG. 1, the metering pump (reciprocating pump) conveys fluid by performing predetermined reciprocating motion by periodically elastically deforming the two diaphragms 1, 1. The metering pump (reciprocating pump) includes two left and right fluid conveying units 10 and 10 each having diaphragms 1 and 1 inside, and fluid conveying unit 10 that supplies hydraulic oil at an appropriate timing to drive the diaphragms 1 and 1. , 10 and a drive unit (not shown) having an electric motor that generates a rotational motion and a gear for transmitting the rotational force of the electric motor to the drive force supply unit 40. Yes.

  Each fluid conveyance unit 10, 10 is provided between left and right hydraulic oil supply units 31, 31 for supplying hydraulic oil from the driving force supply unit 40 to the diaphragms 1, 1, and between these hydraulic oil supply units 31, 31. The pump head 32 provided and the gas discharge mechanism 20 which discharges | emits the gas mixed in the hydraulic oil in the hydraulic oil supply parts 31 and 31 outside are provided. Each fluid conveyance part 10 and 10 is comprised by clamping each diaphragm 1 and 1 using the pump head 32 and the hydraulic oil supply parts 31 and 31 on either side.

  A diaphragm drive chamber 2 including the diaphragm 1 is configured by using the hydraulic oil supply unit 31 and the pump head 32. Further, a hydraulic oil restriction chamber 5 having valve bodies 3 and 3 connected to the diaphragms 1 and 1 and corresponding valve seats 4 and 4 is provided in the hydraulic oil supply units 31 and 31. .

  Further, the pump head 32 is provided with an inflow side check valve 33 that functions to allow the carrier fluid to flow in and an outflow side check valve 34 that functions to cause the carrier fluid to flow out. The fluid flows into the fluid transfer chamber 2a of the diaphragm drive chamber 2 through the inflow path 33a and the inflow side check valve 33, and flows out to the predetermined transfer path through the outflow side check valve 34 and the outflow path 34a.

  The diaphragm drive chamber 2 is configured such that the diaphragms 1 and 1 receive the driving force from the driving unit via the driving force supply unit 40, and the diaphragms 1 and 1 reciprocate based on the driving force. Specifically, the driving force supply unit 40 and the hydraulic oil supply units 31 and 31 are communicated with each other through the hydraulic oil piping units 35 and 35, and the hydraulic oil piping units 35 and 35 and the hydraulic oil supply units 31 and 31 are inside. Filled with hydraulic oil, reciprocating movements of piston parts 43 and 44 of a driving force supply unit 40, which will be described later, are applied to the diaphragm via the hydraulic oil in the hydraulic oil pipes 35 and 35 and the hydraulic oil supply units 31 and 31. 1 and 1 are transmitted.

  The valve bodies 3, 3 in the hydraulic oil restriction chambers 5, 5 are attached to the valve body support portions 6, 6 via biasing means 7, 7 such as coil springs, and the hydraulic oil restriction chambers 5, 5 It is fixed to shafts 8 and 8 communicating with the diaphragm drive chambers 2 and 2.

  One end of each shaft 8, 8 is in contact with the surface of the diaphragm 1, 1 on the side of the hydraulic oil restriction chamber 5, 5, and the diaphragm 1, 1 side through the biasing means 7, 7 and the valve body 3, 3. It has come to be energized.

  Between the hydraulic oil restriction chambers 5 and 5 and the diaphragm drive chambers 2 and 2, shaft support portions 9 and 9 for supporting the shafts 8 and 8 are provided. A through-hole for allowing the working oil to flow from the oil restriction chambers 5 and 5 to the diaphragm drive chambers 2 and 2 is formed. Similarly, the valve body support portion 6 is also formed with a through-hole for circulating hydraulic oil.

  Due to the hydraulic oil restriction chambers 5 and 5 having the above-described configuration, the diaphragms 1 and 1 are elastically deformed by the hydraulic oil flowing into the hydraulic oil supply units 31 and 31 via the hydraulic oil piping portions 35 and 35, and are reciprocated predetermined. Sometimes, the valve body 3 reciprocates together with the diaphragms 1 and 1. When an excessive pressure is applied to the hydraulic oil restriction chambers 5 and 5, the valve body 3 moves and comes into contact with the valve seat 4.

  Thus, the hydraulic oil restriction chambers 5 and 5 can prevent the diaphragms 1 and 1 from being damaged by preventing excessive pressure from being applied to the diaphragms 1 and 1. In addition, relief mechanisms 37 and 37 are provided between the hydraulic oil restriction chambers 5 and 5 and the driving force supply unit 40, and when an excessive pressure is applied to the hydraulic oil restriction chambers 5 and 5, The relief mechanisms 37, 37 can discharge a predetermined amount of hydraulic oil and maintain the pressure in an appropriate state.

  This metering pump (reciprocating pump) is formed with diaphragm drive chambers 2 and 2 and hydraulic oil restriction chambers 5 and 5, so that when a gas such as air is mixed into the hydraulic oil, Gas tends to accumulate at the top of 5. Therefore, in order to properly discharge the gas in the diaphragm drive chambers 2 and 2 and the hydraulic oil restriction chambers 5 and 5, the gas discharge mechanism 20 is provided in a metering pump (reciprocating pump). The gas discharge mechanism 20 is discharged through a first gas discharge path 21 provided in the hydraulic oil restriction chamber 5, a second gas discharge path 22 provided in the diaphragm drive chamber 2, and these gas discharge paths 21 and 22. A flow rate adjusting unit 25 that adjusts the flow rates of the gas and hydraulic oil.

  One end of the first gas discharge path 21 is provided above the valve seat 4 in the hydraulic oil restriction chamber 5 on the hydraulic oil piping part 35 side, and the first gas discharge path 22 has one end thereof. Is provided at an upper position between the diaphragm 1 and the valve seat 4 in the diaphragm drive chamber 2.

  The other ends of the discharge paths 21 and 22 are provided close to each other so as to communicate with a communication part 24 formed between the flow rate adjustment part 25 and the hydraulic oil supply part 31. Furthermore, ball bodies 23 and 23 (backflow prevention bodies) for preventing backflow are provided on the first gas discharge path 21 and the second gas discharge path 22, respectively.

  The flow rate adjustment unit 25 includes a ball body 28 for preventing a backflow and an adjustment valve 27 that adjusts the lift amount (movable region) of the ball body 28. The adjustment valve 27 has an in-valve discharge path therein. A male screw portion is formed on the outer peripheral portion of the adjusting valve 27 so as to be screwed to the flow rate adjusting portion 25, and the lift amount of the ball body 28 is adjusted by the screwing amount of the adjusting valve 27. Yes. The flow rate adjustment unit 25 can adjust the flow rate of the gas and hydraulic oil flowing through the flow rate adjustment unit 25 by adjusting the lift amount of the ball body 28 by the adjustment valve 27.

  Further, the flow rate adjusting units 25, 25 are connected to the hydraulic oil storage unit (inside the casing 50) of the driving force supply unit 40 via the fluid discharge piping unit 36. In addition, a protective cover 29 that covers the adjustment valve 27 and is detachable (or openable / closable) when adjusting the adjustment valve 27 is provided above the adjustment valve 27 in the flow rate adjustment unit 25.

  In the gas discharge mechanism 20 configured as described above, the gas mixed into the diaphragm drive chamber 2 and the hydraulic oil restriction chamber 5 is obtained by operating the adjustment valve 27 so that the ball body 28 can be moved by a predetermined lift amount. However, the ball bodies 23, 23 and 28 are pushed up through the first gas discharge path 21 and the second gas discharge path 22, and are discharged to the outside through the in-valve discharge path of the adjustment valve 27. Further, the hydraulic oil that overflows with the discharge of the gas is collected by the driving force supply unit 40 through the fluid discharge piping unit 36.

  The driving force supply unit 40 reciprocates according to the movement of the driving force transmission shaft 41 receiving the driving force from the gear of the driving unit, the eccentric cam 42 attached to the driving force transmission shaft 41, and the eccentric cam 42. The piston part (first piston part 43 and second piston part 44), the first rotating shaft 45 supported by the inner ring of the bearing 47 in the first piston part 43, and the bearing 48 in the second piston part 44 Provided in each piston part 43, 44 by appropriately energizing the first piston part 43 and the second piston part 44 within the second rotating shaft 46 supported by the inner ring and the second piston part 44. The position regulating biasing means 49 that is an adjusting means that functions to bring the rotating shafts 45 and 46 into contact with the eccentric cam 42, and a casing portion 50 that contains these elements, and the like. Yes. And in the driving force supply part 40 which has the above elements, the hydraulic fluid is filled in the sealed space between the inner wall of the casing part 50 and the piston parts 43 and 44.

  In the driving force supply unit 40, the second piston portion 44 is formed in a hollow shape. That is, the second piston portion 44 is formed so that the driving force transmission shaft 41, the eccentric cam 42, the first piston portion 43, the bearing 48, the position restriction biasing means 49, and the like can be included therein. .

  A position restriction urging means 49 is sandwiched between the inner wall portion (inner surface portion) of the second piston portion 44 and the outer wall portion (outer surface portion) of the first piston portion 43. In other words, the first piston portion 43 and the second piston portion 44 are biased in the direction in which the eccentric cam 42 is positioned by the position regulation biasing means 49. In other words, the position restricting and biasing means 49 always causes the first rotating shaft 45 in the first piston portion 43 and the second rotating shaft 45 in the second piston portion 44 to always have the outer periphery of the eccentric cam 42. It will be properly biased to contact the surface.

  The driving force supply unit 40 collects hydraulic oil from the gas discharge mechanism 20 to the driving force supply unit 40 through the fluid discharge pipe unit 36 corresponding to the first piston unit 43 and the second piston unit 44. In order to prevent a decrease in driving force due to this, auxiliary plunger mechanisms 60 and 60 and hydraulic oil supply valves 70 and 70 are provided.

  The metering pump (reciprocating pump) according to the present embodiment functions as follows during normal operation. The metering pump (reciprocating pump) first rotates the electric motor of the drive unit, and transmits this rotational force to the drive force transmission shaft 41 via a gear.

  Next, the eccentric cam 42 is rotated by the driving force transmission shaft 41, and the first and second piston portions 43 and 44 are reciprocated by the rotation of the eccentric cam 42. Here, based on the above-described configuration, the first piston portion 43 and the second piston portion 44 reciprocate integrally with one eccentric cam 42. The reciprocating motion of the piston portions 43 and 44 causes a predetermined force and direction of pressure to act on the hydraulic oil, and the hydraulic oil is sent to and discharged from the pipe portions 35 and 35.

  Next, the diaphragms 1 and 1 reciprocate at an appropriate timing based on the pressure of the hydraulic fluid flowing through the piping portions 35 and 35, and the movement of the diaphragms 1 and 1 causes the inflow check valve 33 and The outflow side check valve 34 is operated, and a desired liquid is conveyed.

  During normal operation, the metering pump (reciprocating pump) according to the present embodiment is capable of quantitatively determining the desired fluid by causing the constituent elements to function as described above and causing the diaphragms 1 and 1 to reciprocate repeatedly. Can be conveyed. In addition, this metering pump (reciprocating pump) can convey the fluid without pulsation by making the reciprocating motions of the two diaphragms 1 and 1 different.

  As shown in FIG. 2, the diaphragms 1 and 1 used for the above-described metering pump (reciprocating pump) have a thin film shape with a circular shape in plan view. In this embodiment, the diaphragms 1 and 1 have a constant diameter of about 100 mm and a thickness of about 0.1 mm.

  Moreover, as shown in the modification of FIG. 3, the diaphragm can employ a configuration in which the outer edge portion is thicker than the central portion (not shown). In this modification, an outer edge portion (hereinafter referred to as “thick portion”) 1b having a thick wall is formed in an annular shape in plan view, and a predetermined elastic deformation is applied to the inside of the ring of the thick portion 1b. A film portion 1a for transporting the transport fluid is formed. In this modification, the film part 1a and the thick part 1b are integrally formed of the same titanium alloy described later.

  In the diaphragm 1 according to this modification, the thickness of the film portion 1a and the thickness of the thick portion 1b are constant, and the thickness of the thick portion 1b is equal to the central portion (of the film portion 1a). It is desirable that the thickness is not less than three times the thickness of the central portion. In this way, when the diaphragm 1 is sandwiched between the pump head 32 and the hydraulic oil supply units 31 and 31, for example, the thick portion (outer edge portion) 1 b configured to be thick is thick. When the part 1b is elastically deformed (shrinked) in the thickness direction, the part 1b is firmly and reliably fixed, and the sealing performance is thereby improved. Further, the diaphragm 1 is formed of the same titanium alloy for the film part 1a and the thick part 1b, so that the durability and corrosion resistance are good, and the manufacturing cost can be reduced.

  Further, as described above, the diaphragm 1 according to this modified example has 0.0003 ≦ when the thickness of the central portion (the thickness of the central portion of the film portion 1a) is t and the diameter is D. It is preferable that t / D ≦ 0.02, more preferably 0.001 ≦ t / D ≦ 0.02, and further 0.002 ≦ t / D ≦ 0.015. It is most desirable. When t / D is smaller than 0.0003, the pressure resistance is lowered, which is not preferable. On the other hand, if t / D is larger than 0.02, the elastic deformability of the diaphragm 1 is lowered, and a sufficient discharge amount cannot be secured, which is not preferable.

  Further, as shown in the modification of FIG. 4, the diaphragm is prepared by separately preparing a film part 1a and a thick member 1b thicker than the film part 1a in advance, and fixing them by means such as welding. By doing so, it is also possible to form the outer edge part 1b of the film part 1a thickly (thick part). In this modification, the film part 1a is made of a predetermined titanium alloy (described later) as in the modification of FIG. 3, and the thick part 1b is made of, for example, metal titanium (Ti). In this modification, the outer periphery of the film part 1a is sandwiched between two thick parts 1b and 1b configured in an annular shape, and the thick parts 1b and 1b are fixed to the film part 1a.

  Thus, by separating the titanium alloy film part 1a and the metal titanium thick part 1b from each other and fixing the thick part 1b to the film part 1a by means such as welding, the diaphragm 1 The outer edge portion is made of metal titanium, and the physical properties (for example, the coefficient of thermal expansion) of the outer edge portion can be made close to the center portion (film portion 1a), thereby improving durability. And so on.

  Each of the diaphragms 1 and 1 is made of a titanium alloy having a low Young's modulus and a high elastic deformability. Hereinafter, this titanium alloy will be described.

  The average Young's modulus and tensile elastic limit strength related to the titanium alloy used for the diaphragm will be described below with reference to FIGS. FIG. 5 is a diagram schematically showing a stress-elongation (strain) diagram of a titanium alloy, and FIG. 6 is a stress-elongation (strain) diagram of a conventional titanium alloy (Ti-6Al-4V alloy). FIG.

  As shown in FIG. 6, in the conventional metal material, first, the elongation linearly increases in proportion to the increase in tensile stress (between A ′ and A). And the Young's modulus of the conventional metal material is calculated | required by the inclination of the straight line. In other words, the Young's modulus is a value obtained by dividing the tensile stress (nominal stress) by the strain (nominal strain) proportional to the tensile stress. Thus, in the linear region (between A ′ and A) in which stress and elongation (strain) are in a proportional relationship, the deformation is elastic. For example, if the stress is unloaded, the elongation that is the deformation of the test piece is Return to zero. However, when a tensile stress is further applied beyond the linear region, the conventional metal material starts plastic deformation, and even when the stress is unloaded, the elongation of the test piece does not return to 0 and a permanent elongation occurs.

  Usually, the stress σp at which the permanent elongation is 0.2% is referred to as 0.2% proof stress (JIS Z 2241). The 0.2% proof stress is a straight line obtained by translating a straight line in the elastic deformation region (A′-A: tangent to the rising portion) by 0.2% elongation (strain) on the stress-elongation (strain) diagram. It is also the stress at the intersection (position B) between (B′-B) and the stress-elongation (strain) curve. In the case of a conventional metal material, it is generally considered that 0.2% proof stress≈tensile elastic limit strength based on an empirical rule that “when elongation exceeds about 0.2%, permanent elongation occurs”. Conversely, within this 0.2% proof stress, the relationship between stress and strain is considered to be generally linear or elastic.

  However, as can be seen from the stress-elongation (strain) diagram of FIG. 5, such a conventional concept does not apply to titanium alloys. The reason is not clear, but in the case of titanium alloy, the stress-elongation (strain) diagram does not become a straight line in the elastic deformation region, but becomes an upwardly convex curve (A'-B). Elongation returns to 0 along -A 'or permanent elongation occurs along BB'. Thus, in the titanium alloy, even in the elastic deformation region (A′-A), the stress and elongation (strain) are not in a linear relationship, and if the stress increases, the elongation (strain) increases rapidly. . The same applies to unloading, where the stress and elongation (strain) are not in a linear relationship, and if the stress decreases, the elongation (strain) decreases rapidly. Such a feature seems to be manifested as a high elastic deformability of the titanium alloy.

  In the case of a titanium alloy, as can be seen from FIG. 5, the slope of the tangent line on the stress-elongation (strain) diagram decreases as the stress increases. Thus, since the stress and elongation (strain) do not change linearly in the elastic deformation region, it is not appropriate to define the Young's modulus of the titanium alloy by the conventional method. In the case of a titanium alloy, since stress and elongation (strain) do not change linearly, it is not appropriate to evaluate as 0.2% proof stress (σp ′) ≈tensile elastic limit strength by the same method as before. . In other words, the 0.2% yield strength obtained by the conventional method becomes a value that is significantly smaller than the original tensile elastic limit strength, and can no longer be considered as 0.2% yield strength≈tensile elastic limit strength.

  Therefore, returning to the original definition, the tensile elastic limit strength (σe) of the titanium alloy is obtained as described above (position B in FIG. 5), and the Young's modulus of the titanium alloy is used as the average Young mentioned above. It was decided to introduce rate. 5 and 6, σt is the tensile strength, εe is the elongation (strain) at the tensile elastic limit strength (σe) of the titanium alloy, and εp is the 0.2% proof stress (σp of the conventional metal material) ) In (elongation).

  When the total amount of the titanium alloy is 100% by mass, when one or more elements in the metal element group composed of zirconium (Zr), hafnium (Hf), and scandium (Sc) are contained in a total of 20% by mass or less Is preferable. Zirconium and hafnium are effective in lowering the Young's modulus and increasing the strength of the titanium alloy. In addition, these elements are elements belonging to the same group (IVa group) as titanium, and are neutral elements of all solid solution type, and therefore do not hinder the low Young's modulus of the titanium alloy by the Va group element. Further, scandium is an effective element that, when dissolved in titanium, specifically lowers the Young's modulus by specifically reducing the binding energy between titanium atoms together with the Va group element.

  When the total amount of these elements exceeds 20% by mass, the strength and toughness are reduced due to material segregation, and the cost is increased. In order to balance the Young's modulus, strength, toughness, and the like, it is more preferable that the total amount of these elements is 1% by mass or more, and further 5 to 15% by mass. Further, since these elements have many parts in common with the Va group element, they can be replaced with the Va group element within a predetermined range. That is, the titanium alloy is composed of one or more elements in the metal element group consisting of zirconium (Zr), hafnium (Hf), and scandium (Sc) in a total amount of 20% by mass or less, and one kind in the metal element group. The Va group (vanadium group) element whose total with the above elements is 30 to 60% by mass and the balance is substantially titanium, the average Young's modulus is 75 GPa or less, and the tensile elastic limit strength is 700 MPa or more. Is preferable.

  In addition, the titanium alloy has a total of 20% by mass or less of one or more elements in the metal element group consisting of zirconium (Zr), hafnium (Hf), and scandium (Sc), and one kind in the metal element group. It is preferable that the sintered alloy is composed of a Va group (vanadium group) element whose total amount is 30 to 60% by mass and the balance is substantially titanium. As described above, the total amount of zirconium and the like is 20% by mass or less. Similarly, it is more preferable that the total amount of these elements is 1% by mass or more, and further 5 to 15% by mass.

  When the titanium alloy contains one or more elements in a metal element group consisting of chromium (Cr), molybdenum (Mo), manganese (Mn), iron (Fe), cobalt (Co), and nickel (Ni), Is preferred. More specifically, when the whole is 100% by mass, the chromium and the molybdenum are each 20% by mass or less, and the manganese, the iron, the cobalt, and the nickel are each 10% by mass or less. If there is, it is preferable.

  Chromium and molybdenum are effective elements for improving the strength and hot forgeability of the titanium alloy. When hot forgeability is improved, productivity and yield of the titanium alloy can be improved. Here, when chromium and molybdenum exceed 20% by mass, material segregation easily occurs, and it becomes difficult to obtain a homogeneous material. When these elements are 1% by mass or more, it is preferable for improving the strength and the like by solid solution strengthening, and further preferably 3-15% by mass.

  Manganese, iron, cobalt, and nickel are elements that are effective in improving the strength and hot forgeability of titanium alloys, like molybdenum. Therefore, these elements may be contained in place of molybdenum, chromium or the like or together with molybdenum, chromium or the like. However, if these elements exceed 10% by mass, an intermetallic compound is formed with titanium and ductility is lowered, which is not preferable. When these elements are 1% by mass or more, it is preferable for improving the strength and the like by solid solution strengthening, and more preferably 2-7% by mass.

  When the titanium alloy is a sintered titanium alloy, it is preferable to add tin to the metal element group. That is, the sintered titanium alloy is a metal element group consisting of chromium (Cr), molybdenum (Mo), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), and tin (Sn). It is preferable to include one or more elements. Specifically, when the total is 100% by mass, the chromium and the molybdenum are each 20% by mass or less, and the manganese, the iron, the cobalt, the nickel, and the tin are 10% by mass, respectively. The following is more preferable.

  Tin is an α-stabilizing element and is an effective element for improving the strength of the titanium alloy. Therefore, 10% by mass or less of tin may be contained together with an element such as molybdenum. When tin exceeds 10 mass%, the ductility of a titanium alloy will fall and workability will fall. When tin is 1 mass% or more, and further 2 to 8 mass%, it is more preferable in terms of increasing the strength as well as reducing the Young's modulus. The elements such as molybdenum are the same as described above.

  The titanium alloy preferably contains aluminum (Al). Specifically, it is more preferable that the aluminum content is 0.3 to 5 mass% when the whole is 100 mass%. Aluminum is an effective element for improving the strength of the titanium alloy. Accordingly, 0.3 to 5% by mass of aluminum may be contained in place of molybdenum or iron or together with these elements. If the aluminum content is less than 0.3% by mass, the solid solution strengthening effect is insufficient and sufficient strength cannot be improved. Moreover, when it exceeds 5 mass%, the ductility of a titanium alloy will be reduced. When aluminum is 0.5-3 mass%, when aiming at the improvement of the stable intensity | strength, it is more preferable. Note that it is more preferable to add aluminum together with tin because the strength can be improved without reducing the toughness of the titanium alloy.

  It is preferable that the titanium alloy contains 0.08 to 0.6% by mass of oxygen (O) when the whole is 100% by mass. Moreover, when the whole is 100 mass%, it is suitable when 0.05-1.0 mass% carbon (C) is included. Moreover, when the whole is 100 mass%, it is suitable when 0.05-0.8 mass% nitrogen (N) is included. In summary, when the total is 100% by mass, 0.08 to 0.6% by mass of oxygen (O), 0.05 to 1.0% by mass of carbon (C), and 0.05 to 0.8%. It is preferable that one or more elements in the element group consisting of nitrogen (N) in mass% are included.

  Oxygen, carbon, and nitrogen are all interstitial solid solution strengthening elements, and are effective elements for stabilizing the α phase of the titanium alloy and improving the strength. If oxygen is less than 0.08 mass% and carbon or nitrogen is less than 0.05 mass%, the strength of the titanium alloy is not sufficiently improved. Moreover, when oxygen exceeds 0.6 mass%, carbon exceeds 1.0 mass%, or nitrogen exceeds 0.8 mass%, the titanium alloy becomes brittle, which is not preferable. When oxygen is 0.1% by mass or more, further 0.15 to 0.45% by mass, it is more preferable in terms of the balance between the strength and ductility of the titanium alloy. Similarly, 0.1 to 0.8% by mass of carbon and 0.1 to 0.6% by mass of nitrogen are more preferable in terms of the balance between strength and ductility.

  When the titanium alloy is 100% by mass as a whole, it is preferable that the titanium alloy contains 0.01 to 1.0% by mass of boron (B). Boron is an element effective in improving the mechanical material properties and hot workability of the titanium alloy. Boron hardly dissolves in the titanium alloy, and almost all of it precipitates as titanium compound particles (TiB particles or the like). This is because the precipitated particles remarkably suppress the crystal grain growth of the titanium alloy and keep the structure of the titanium alloy fine. If boron is less than 0.01% by mass, the effect is not sufficient. If it exceeds 1.0% by mass, the number of highly rigid precipitated particles increases, resulting in an increase in the overall Young's modulus of the titanium alloy and cold working. This is because it causes a decline in sex.

  In addition, when 0.01 mass% boron is added, it becomes 0.055 volume% when converted in terms of TiB particles, whereas when 1 mass% boron is added, it is converted into 5.5 volumes when converted in terms of TiB particles. %. Therefore, in other words, the titanium alloy preferably has titanium boride particles in the range of 0.055 volume% to 5.5 volume%. By the way, the above-mentioned composition elements can be arbitrarily combined within a predetermined range. Specifically, the above-mentioned Zr, Hf, Sc, Cr, Mo, Mn, Fe, Co, Ni, Sn, Al, O, C, N, and B are appropriately and selectively combined within the above range, and titanium. It can also be an alloy. However, this does not exclude the addition of another element within a range not departing from the spirit of the titanium alloy.

  The cold work structure is a structure obtained when a titanium alloy is cold worked. “Cold” means that the temperature is sufficiently lower than the recrystallization temperature of the titanium alloy (the lowest temperature at which recrystallization occurs). Although the recrystallization temperature varies depending on the composition, it is about 600 ° C., and the titanium alloy is usually cold-worked in the range of room temperature to 300 ° C.

  Moreover, the cold work structure | tissue of X% or more means the cold work structure | tissue produced when the cold work rate defined by following Formula is X% or more.

Cold working rate X = (S ₀ −S) / S ₀ × 100 (%)
(S ₀ : sectional area before cold working, S: sectional area after cold working)

  Such cold working imparts a working strain in the titanium alloy. This processing strain is considered to bring about a microscopic structural change at the atomic level in the structural structure and contribute to the reduction of the Young's modulus of the titanium alloy. In addition, it is considered that the accumulation of elastic strain accompanying the microscopic structural change at the atomic level due to the cold working contributes to the improvement of the strength of the titanium alloy.

  Specifically, it is preferable that it has a cold-worked structure of 10% or more, an average Young's modulus is 70 GPa or less, and a tensile elastic limit strength is 750 MPa or more. By imparting cold working, the lower Young's modulus, higher elastic deformability and higher strength of the titanium alloy can be further advanced. Further, the titanium alloy preferably has the cold-worked structure of 50% or more, an average Young's modulus of 65 GPa or less, and a tensile elastic limit strength of 800 MPa or more. Furthermore, it is more preferable that the titanium alloy has the cold-worked structure of 70% or more, the average Young's modulus is 60 GPa or less, and the tensile elastic limit strength is 850 MPa or more. Further, the titanium alloy is particularly suitable when it has the cold-worked structure of 90% or more, the average Young's modulus is 55 GPa or less, and the tensile elastic limit strength is 900 MPa or more.

  The titanium alloy can have a cold working rate of 99% or more, and although details are not clear, it is clearly different from conventional titanium alloys. Even when compared with a conventional titanium alloy excellent in cold workability (for example, Ti-22V-4Al: usually DAT51, etc.), the cold work rate of the titanium alloy is an astonishing value. In this way, titanium alloys are extremely excellent in cold workability, and the physical properties and mechanical properties of cold work tend to be further improved, so that high elastic deformability and high strength are achieved with a low Young's modulus. It is the optimum material for various cold-worked molded products that are required.

  A sintered alloy is an alloy obtained by sintering raw material powder. When the titanium alloy is a sintered titanium alloy, it exhibits low Young's modulus, high elastic deformability, high strength, and excellent cold workability. For example, the sintered titanium alloy can have an average Young's modulus of 75 GPa or less and a tensile elastic limit strength of 700 MPa or more. Furthermore, the sintered titanium alloy can adjust the amount of pores in its structure to adjust the Young's modulus, strength, density, and the like. For example, it is preferable that the sintered alloy contains pores of 30% by volume or less. This is because by setting the pores to 30% by volume or less, the average Young's modulus can be significantly reduced even with the same alloy composition.

  On the other hand, if the sintered alloy has a structure in which pores are densified to 5% by volume or less by hot working, a new feature is imparted, which is preferable. That is, when the sintered alloy is densified by hot working, in addition to the low Young's modulus, high elastic deformability, and high strength, the titanium alloy can have excellent cold workability. And it is more suitable when a void | hole is reduced to 1 volume% or less. The hot working means plastic working at a recrystallization temperature or higher, and examples thereof include hot forging, hot rolling, hot swage, HIP, and the like.

Moreover, a void | hole means the space | gap which remains in a sintered alloy, and is evaluated by relative density. The relative density is expressed as a percentage (ρ / ρ ₀ ) × 100 (%) of a value obtained by dividing the density ρ of the sintered body by the true density ρ ₀ (in the case of 0% residual voids), and the volume of the voids. % Is expressed by the following equation.
Hole volume% = {1- (ρ / ρ ₀ )} × 100 (%)
For example, when the metal powder is CIP-molded (cold isostatic pressing), the volume of pores can be easily adjusted by adjusting the hydrostatic pressure (for example, ² to 4 ton / cm ² ). The size of the pores is not particularly limited. For example, if the average diameter is 50 μm or less, the uniformity of the sintered alloy is maintained and the strength reduction is suppressed. Has ductility. Here, the average diameter means the average diameter of the circle calculated by replacing the holes measured by the two-dimensional image processing with a circle having an equivalent cross-sectional area.

  The raw material powder required for the sintering method contains at least titanium and a Va group element. However, they can take a wide variety of forms. For example, the raw material powder may further contain Zr, Hf, Sc, Cr, Mo, Mn, Fe, Co, Ni, Sn, Al, O, C, N, and B. Specifically, for example, when the raw material powder is 100% by mass as a whole, the total of one or more elements in the metal element group consisting of zirconium (Zr), hafnium (Hf), and scandium (Sc) is added. It is preferable that the content is 20% by mass or less.

  The manufacturing method includes titanium, one or more elements in a metal element group composed of zirconium (Zr), hafnium (Hf), and scandium (Sc) in a total amount of 20% by mass or less, and the metal element group. A mixing step of mixing at least two kinds of raw material powders including a Va group (vanadium group) element whose total amount with one or more types of elements is 30 to 60% by mass, and mixing obtained by the mixing step A molding step of molding the powder into a molded body having a predetermined shape, and a sintering step of heating and sintering the molded body obtained in the molding step at 1200 to 1400 ° C. for 2 to 16 hours. This is preferable.

  In addition, this manufacturing method includes titanium, one or more elements in a metal element group composed of zirconium (Zr), hafnium (Hf), and scandium (Sc) in a total amount of 20% by mass or less, and the metal element group. A filling step of filling a container having a predetermined shape with a raw material powder containing at least a Va group (vanadium group) element with a total of 30 to 60% by mass of one or more elements therein, and a hot static after the filling step It is preferable to use a sintering process in which the raw material powder in the container is sintered under the conditions of 900 to 1300 ° C. and 1 to 10 hours using a hydraulic method (HIP method). It is preferable that the raw material powder further contains at least one element of chromium, manganese, cobalt, nickel, molybdenum, iron, tin, aluminum, enzyme, carbon, nitrogen and boron.

  When this manufacturing method involves a mixing step, it is preferable that the raw material powder is composed of two or more of pure metal powder and / or alloy powder. Specific examples of usable powders include sponge powder, hydrodehydrogenated powder, hydrogenated powder, and atomized powder. The particle shape and particle size (particle size distribution) of the powder are not particularly limited, and commercially available powders can be used as they are. However, it is preferable that the used powder has an average particle size of 100 μm or less from the viewpoint of cost and compactness of the sintered body. Furthermore, if the particle size of the powder is 45 μm (# 325) or less, a denser sintered body can be easily obtained.

  When this manufacturing method uses the HIP method, it is preferable that the raw material powder is made of an alloy powder containing titanium and at least a Va group element. This alloy powder is a powder having a titanium alloy composition, for example, hydrogenating an ingot produced by a gas atomizing method, a REP method (rotating electrode method), a PREP method (plasma rotating electrode method), or a melting method. Then, it is manufactured by a method of pulverizing, further MA method (mechanical alloying method) or the like.

  A mixing process is a process of mixing raw material powder. A V-type mixer, a ball mill and a vibration mill, a high energy ball mill (for example, an attritor) or the like can be used for mixing them.

  The molding step is a step of molding the mixed powder obtained in the mixing step into a molded body having a predetermined shape. The shape of the molded body may be the final shape of the product, or may be a billet shape when further processing is performed after the sintering process. In the molding step, for example, die molding, CIP molding (cold isostatic pressing), RIP molding (rubber isostatic pressing), or the like can be used.

  The filling step is a step of filling the above-mentioned raw material powder containing titanium and at least a Va group element into a container having a predetermined shape, and is necessary for using a hot isostatic pressure method (HIP method). The inner shape of the container filled with the raw material powder corresponds to a desired product shape. The container may be made of metal, ceramic, or glass, for example. Further, it is preferable to vacuum degas and fill and enclose the raw material powder in a container.

  The sintering step is a step of heating and sintering the molded body obtained in the molding step to obtain a sintered body, or a hot isostatic pressure method (HIP) after the filling step. This is a step of solidifying the powder under pressure. When sintering a molded object, it is preferable to make in the atmosphere of a vacuum or an inert gas. The sintering temperature is preferably not higher than the melting point of the alloy and in a temperature range where the component elements are sufficiently diffused. For example, the temperature range is 1200 ° C to 1400 ° C. The sintering time is preferably 2 to 16 hours. Therefore, in order to increase the density and productivity of the titanium alloy, the sintering process is preferably performed under conditions of 1200 ° C. to 1400 ° C. and 2 to 16 hours.

  In the case of the HIP method, it is preferable to carry out in a temperature range in which diffusion is easy, the deformation resistance of the powder is small, and the reaction with the container is difficult. For example, the temperature range is 900 ° C to 1300 ° C. Moreover, it is preferable that a shaping | molding pressure is a pressure which can fully carry out creep deformation of a filling powder, for example, the pressure range is 50-200 Mpa (500-2000 atmospheres). The HIP treatment time is preferably a time during which the powder is sufficiently creep deformed and densified, and the alloy component can diffuse between the powders. For example, the time is 1 hour to 10 hours.

  By performing hot working, the pores and the like of the sintered alloy can be reduced and the structure can be densified. Therefore, it is preferable that this manufacturing method further includes a hot working step in which the sintered body obtained after the sintering step is hot worked to densify the structure of the sintered body. This hot working may be performed to form a rough product shape.

  Since the titanium alloy obtained by this production method is excellent in cold workability, various products can be produced by cold working the obtained sintered body. Therefore, it is preferable that this manufacturing method further includes a cold working step in which the sintered body obtained after the sintering step is cold worked to form a material or a product. And after performing roughing by the said hot processing, you may finish by cold processing.

  According to the diaphragms 1 and 1 formed of the titanium alloy described above, by being formed of the titanium alloy as described above, it has a low elastic modulus and a low Young's modulus. Desired elastic deformation can be realized without making it extremely large. Accordingly, the metering pump (reciprocating pump) configured using the diaphragms 1 and 1 can be configured to be as small as possible, and is particularly useful in this respect. Similarly, a device using the diaphragms 1 and 1 can be miniaturized as much as possible.

It is a schematic sectional drawing of the metering pump (reciprocating pump) which concerns on embodiment of this invention. The diaphragm which concerns on embodiment of this invention is shown, (a) is the top view, (b) is the side view. It is sectional drawing which shows the other modification of the diaphragm which concerns on embodiment of this invention. It is sectional drawing which shows the other modification of the diaphragm which concerns on embodiment of this invention. It is the figure which showed typically the stress-elongation (distortion) diagram of the titanium alloy used for a diaphragm. It is the figure which showed typically the stress-elongation (distortion) diagram of the conventional titanium alloy.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Diaphragm, 1a ... Film | membrane part, 1b ... Thick part, 2 ... Diaphragm drive chamber, 3 ... Valve body, 4 ... Valve seat, 5 ... Hydraulic oil restriction chamber, 6 ... Valve body support part, 7 ... Energizing means , 8 ... shaft, 9 ... shaft support part, 10 ... fluid conveying part, 20 ... gas discharge mechanism, 21 ... first gas discharge path, 22 ... second gas discharge path, 23 ... ball body, 24 ... communication part, 25 DESCRIPTION OF SYMBOLS ... Flow adjustment part, 26 ... Restriction part, 27 ... Adjustment valve, 28 ... Ball body, 29 ... Protection cover, 31 ... Hydraulic oil supply part, 32 ... Pump head, 33 ... Inflow side check valve, 34 ... Outflow side reverse Stop valve, 35 ... hydraulic oil piping part, 37 ... relief mechanism, 40 ... driving force supply part, 41 ... driving force transmission shaft, 42 ... eccentric cam, 43 ... first piston part, 44 ... second piston part, 45 ... First rotating shaft, 46 ... second rotating shaft, 47 ... bearing, 48 ... bearing, 49 Position regulating biasing means, 50 ... casing, 60 ... auxiliary plunger mechanism, 70 ... hydraulic oil supply valve

Claims (5)

A diaphragm for a metering pump capable of conveying a fluid by a predetermined elastic deformation,
30 to 60% by mass of a Va group (vanadium group) element and the balance substantially consisting of titanium,
In the elastic deformation region, the tensile elastic limit strength defined as the stress when the permanent set reaches 0.2% in the tensile test is 700 MPa or more, and the applied stress is in the range from 0 to the tensile elastic limit strength. The slope of the tangent line on the stress-strain diagram obtained by the tensile test shows a characteristic that decreases as the stress increases,
As a representative value of the Young's modulus obtained from the slope of the tangent on the stress-strain diagram, the average Young's modulus obtained from the slope of the tangent at the stress position corresponding to 1/2 of the tensile elastic limit strength is 75 GPa or less. A diaphragm for a metering pump, characterized by being formed of a titanium alloy having high elastic deformability.   The diaphragm for a metering pump according to claim 1, wherein the diaphragm is formed in a circular shape, and the thickness is t and the diameter is D, 0.0003 ≦ t / D ≦ 0.02.   The diaphragm for metering pumps according to claim 1 or 2 whose thickness of the outer edge part is thicker than the thickness of the central part.   The diaphragm for metering pumps according to any one of claims 1 to 3, wherein a thickness of the outer edge portion is three times or more of a thickness of the central portion.   The diaphragm for metering pumps according to any one of claims 1 to 4, wherein an outer edge portion of the titanium alloy or metal titanium is formed in an annular shape.

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